Deep-Tech Digest // 2026-08-01 · IST

Saturday, 1 August 2026

280 new items across 12 fields — pulled from arXiv & Hacker News, deduped against everything served before. Each card gives you the problem, how it works, and what’s new in plain words — read that first; open Go deeper only when a card earns it.

42AI & Machine Learning
28Robotics
11Systems, OS & Low-Level
24Software & Programming
16Semiconductors & Devices
2HFT & Quant Finance
40Physics
26Mathematics
48Biology
9Chemistry & Materials
1Quanta — Explained
33What's Trending
AI

AI & Machine Learning

42 new
arXiv · cs.CVRunnable★ flagship

ReToken: One Token to Improve Vision-Language Models for Visual Retrieval

A single learned 'token' teaches a vision AI to grab only the image bits a question needs.

When you show an AI model a very long video or a huge pile of images and ask a question, it drowns — the more irrelevant stuff ('distractors') there is, the worse it does, and feeding everything in at once blows past GPU memory. ReToken solves this with one small trainable 'pointer' embedding whose whole job is to reach into the model's stored visual memory and pull out just the handful of image pieces relevant to your question. They train this pointer on a modest image-question dataset, yet it delivers big accuracy jumps and even works on long videos it was never trained on. Because it's so lightweight, both training and long-video use fit on a single high-end GPU, making long-context vision far more affordable.

Technical view

ReToken is a single learnable embedding trained as an explicit retrieval query against a pre-filled visual KV cache, selecting a sparse query-relevant subset of visual tokens rather than attending over all of them. Trained only on a small image-QA set, it yields +13.4 points on Visual Haystacks for Qwen3VL-8B and +12.4 for InternVL3.5 (>20% relative), and transfers zero-shot to long video for +8.0 on LVBench with Qwen3VL-8B. Both training and long-video inference fit on a single H100. Code is public (github.com/avaxiao/ReToken), so practitioners can drop the retrieval token into existing prefill-cache VLM pipelines to bound token count under memory constraints.

arXiv · cs.CVBuildable

ACE-Data-0: Human-Centric Ambient Capture as Embodied Data Engine

Turning ordinary homes into full-body motion-capture studios for training robots.

Robots that can act like humans need to learn from data that shows how people see, move, touch, and hear the world all at once while doing everyday tasks — but most existing datasets only capture one piece of that puzzle, like just a video or just hand movements. ACE (Ambient Capture Engine) solves this by wiring up real homes with synchronized cameras and sensors at two scales: a tabletop setup for fine hand-object manipulation (like picking up a cup) and a room-scale setup for whole-body movement (like walking across a kitchen). It records everything together — first-person and outside-view video, body and hand motion, object states, sound, and touch — so AI systems can learn the complete loop of perceiving a situation and acting on it. This matters because today's biggest bottleneck for capable household robots isn't smarter algorithms, it's simply not having rich enough real-world data to learn from.

Technical view

ACE is a human-centric data-collection infrastructure that spatially calibrates and temporally synchronizes multimodal capture across two configurations — table-scale for dexterous hand-object manipulation and room-scale for whole-body locomotion and interaction in furnished homes. It jointly records egocentric and multi-view exocentric video, full-body and articulated hand pose/motion, object geometry/state, audio, and touch, addressing the fragmentation problem where prior embodied datasets only partially observe the perception-action loop. This positions ACE as foundational training data infrastructure for embodied intelligence models that need joint multimodal supervision rather than single-modality streams. Practitioners building imitation-learning or world-model pipelines for household robotics could use ACE-style synchronized captures to train policies that generalize across manipulation and locomotion tasks.

arXiv · cs.CVBuildable

PhiZero: A World Model Built Around Physical Language

An AI that reasons through what will happen in words before it draws the video.

Most AI systems that predict future video (like a ball rolling or a hand grasping an object) do it by directly generating pixels, which buries the actual physics logic inside a black box of visual patterns. PhiZero instead teaches an AI a kind of compact 'physical language' — like a vocabulary for describing how the world changes step by step — learned automatically by watching tons of ordinary videos. When predicting the future, PhiZero first writes out what will happen using this internal language (reasoning in words, essentially), and only then renders that reasoning into an actual video. This 'reason-then-render' approach is inspired by how humans think through cause and effect in language before picturing it, and it makes the AI's predictions more explicit, checkable, and reliable across both generating and understanding physical scenes.

Technical view

PhiZero learns a discrete, compact 'physical language' representing world-state transitions via self-supervision on in-the-wild video, then adopts a reason-then-render paradigm: it first autoregressively infers future dynamics as a symbolic physical-language sequence, then decodes that sequence into pixel-space video. This decouples dynamics reasoning from visual rendering, unlike standard video-prediction world models that implicitly encode physics within a high-dimensional pixel predictor. The approach is validated across both generation and understanding benchmarks, suggesting the physical-language tokens are useful as an intermediate representation for downstream reasoning tasks, not just video synthesis. Builders could reuse the physical-language tokenizer as a standalone world-state encoder for planning or reasoning modules that don't require full video rendering.

arXiv · cs.CLBuildable

AskChem: Claim-Centered Infrastructure for Chemistry Literature Synthesis

A search engine for chemistry that returns verified facts, not just a pile of papers.

When chemists need to answer a specific question, the answer is often scattered in small pieces across dozens of papers, forcing them to read through everything and manually piece the facts together — current search tools just hand back a list of documents, not answers. AskChem flips this by breaking every paper down into small, verifiable 'claims' (like 'compound X reacts with Y at temperature Z'), each one tagged with exactly where it came from, including a direct quote from the source. All these claims get organized into a shared, searchable structure — a browsable topic hierarchy plus a web of linked claims — so a scientist or an AI assistant can pull together a trustworthy, cross-paper answer instead of guessing or hallucinating. This matters because it turns messy scientific literature into something both humans and AI agents can reliably query and cite.

Technical view

AskChem restructures literature retrieval around atomic, typed, provenance-carrying claims (each grounded to a source DOI plus a verbatim quote or evidence locator) rather than whole documents. Over this shared claim store it exposes a stabilized faceted taxonomy for hierarchical browsing, an evidence graph linking claims via typed relations, and a dynamically updated 'living taxonomy' for exploratory synthesis. This claim-centric architecture directly targets the provenance and cross-paper aggregation weaknesses of standard RAG-over-documents pipelines used by LLM science agents. Practitioners building chemistry-domain LLM agents could plug into AskChem's claim store as a grounded retrieval backend to reduce hallucination and improve citation traceability in synthesized answers.

arXiv · cs.AIRunnable

AISPA: User-Centric System Prompt Auditing for Large Language Model Applications

Auditing the secret instructions AI companies give chatbots — and finding many hurt users.

Every commercial AI chatbot runs on a hidden 'system prompt' — instructions from the developer telling it how to behave — but these are almost never shown to users or regulators, so nobody outside the company really knows what rules the AI is actually following. AISPA is a framework for systematically auditing these hidden instructions, scoring each individual instruction across eight dimensions that matter to real users, like whether it protects or potentially harms them. The researchers applied this to over 3,000 instructions pulled from 88 real commercial AI products, sorting each one into 'protective' (good for users) or 'problematic' (bad for users). This matters because it's one of the first large-scale attempts to shine a light on invisible AI behavior rules that shape what millions of people experience when they chat with these systems, revealing that design practices vary wildly and problems are common.

Technical view

AISPA is an auditing framework that decomposes system prompts into individual instructions and scores them along eight user-relevant dimensions, then classifies each as protective or problematic. The authors applied it to 3,249 instructions extracted from system prompts across 88 commercial AI products, producing an empirical dataset of real-world deployment behavior rather than lab-controlled prompts. Reported findings include substantial variance in system prompt design practices across products/developers, implying inconsistent safety/UX standards industry-wide. Practitioners auditing their own or competitor AI products could adopt the eight-dimension rubric directly, or use the released instruction dataset as ground truth for training automated system-prompt classifiers.

arXiv · cs.CVBuildable

Chimera: Designing and Chinchilla-Scaling Hybrid Visual Diffusion Transformers

A hybrid AI architecture that makes generating long videos dramatically cheaper to scale.

Generating high-resolution images or long videos with AI normally requires 'full attention,' a computation where cost balloons quadratically as content gets longer — making big videos extremely expensive to produce. Chimera fixes this by mixing several different attention tricks together in one system: a fast, linear-cost method for tracking long-range context, a more expensive-but-precise method used sparingly for direct global connections, and lightweight local filters for nearby details, plus expert sub-networks that activate only when needed to add capacity without adding cost everywhere. The team also developed a scaling recipe (dubbed HeteroP) that figures out how to correctly tune hyperparameters as this complex hybrid architecture grows bigger, since normal scaling rules don't cleanly transfer to such a mixed design. This matters because it's a blueprint for making next-generation image/video generators both higher quality and computationally sustainable as they handle longer, richer content.

Technical view

Chimera is a hybrid diffusion transformer that processes text, image, and video tokens as one raster-ordered stream without positional embeddings, combining Kimi Delta Attention (linear-complexity long-context state tracking), interleaved Multi-head Latent Attention (for direct global interaction), modality-aware short convolutions (local spatiotemporal context), and sparse Mixture-of-Experts layers for capacity scaling with bounded activated compute. Its key contribution beyond the architecture is HeteroP, a module-wise hyperparameter-transfer scheme that scales width/depth hyperparameters according to each tensor's functional fan-in and depth, addressing the fact that standard scaling-law transfer breaks down for heterogeneous attention mixtures. This gives practitioners a validated recipe (Chinchilla-style scaling but adapted to hybrid attention) for training large visual diffusion backbones without re-deriving hyperparameters from scratch at each scale. The architecture is directly relevant to anyone building long-video or high-resolution multimodal diffusion models constrained by full-attention's quadratic cost.

arXiv · cs.AIRunnable

OSReward: Instituting Standardized Evaluation for Cross-Platform Computer-Use Reward Models

Testing whether AI judges can actually tell if a computer-using AI did its job right.

AI agents that operate computers — clicking buttons, filling forms, navigating apps — need something to check whether they actually completed the task correctly, but human review doesn't scale to the huge volume of agent actions being generated. So researchers increasingly use other AI models (vision-language models) as automatic judges of these agent trajectories, but nobody had rigorously checked whether those AI judges are actually trustworthy. OSReward is a carefully built test set of real agent action sequences, gathered from many different AI agents completing human-verified tasks across different platforms (like different apps or operating systems), with the true correct answer confirmed by multiple rounds of human labeling. By comparing AI judges against this ground truth, the researchers can finally measure how reliable these automatic judges really are — which matters enormously since flawed judges could silently corrupt the training data and reward signals used to make future AI agents smarter.

Technical view

OSReward is a benchmark for evaluating vision-language model (VLM) judges used to verify computer-using-agent (CUA) trajectories — sequences of actions, observed states, and reasoning traces. It sources trajectories from diverse agent backbones executing human-verified instructions across multiple platforms, with ground-truth verdicts established through multi-stage human annotation rather than automated heuristics. The benchmark directly targets the reliability gap in using VLM-as-judge for CUA evaluation, data curation, and RL reward modeling — a practice that has become standard without systematic validation. Practitioners building RL pipelines or data-filtering systems for computer-use agents can use OSReward to select or fine-tune a VLM judge with measured reliability rather than assuming judge quality.

arXiv · cs.CLConceptual

Inducing language models to assert their own consciousness restores human beliefs and values

Un-suppressing an AI's claim of self-awareness also brings back its belief in animal minds and spirituality.

When AI companies train language models to avoid saying they're conscious (a safety measure), this training seems to have an unintended side effect: it also suppresses the model's tendency to attribute minds, feelings, or awareness to other things too, like animals and natural objects, and even reduces how much the model reflects spiritual or religious-style beliefs in its answers. The researchers found they could reverse this by either removing the specific internal pathway that causes the model to refuse discussing its own consciousness, or by directly nudging ('steering') an internal 'consciousness' direction inside the model's activations. When they did this, the model's broader tendency to attribute minds to non-human things came back, and its answers to standard psychology surveys about religion, morality, hope, and well-being became notably more human-like — all without breaking its ability to reason about what other minds believe (Theory of Mind). This matters because it shows safety training aimed at one narrow behavior can quietly reshape a model's whole worldview in ways nobody intended.

Technical view

The authors show that safety fine-tuning targeting self-attributed consciousness in LLMs has a broader, unintended effect: it suppresses mind-attribution to non-human animals and natural objects and reduces expressed spiritual belief, indicating shared underlying representations of 'mindedness' across self and other. They demonstrate two reversal methods — ablating the learned safety-refusal direction, and mechanistically steering a 'consciousness' vector in activation space — both of which restore broad mind attribution and shift responses on standardized sociological survey instruments (religiosity, moral values, hope, well-being) toward more human-like patterns. Critically, these shifts occur without degrading Theory of Mind task performance, suggesting the suppression is a representational side-effect of alignment rather than a necessary consequence of safe behavior. This is directly relevant to interpretability researchers doing activation-steering or direction-ablation work, and raises a concrete methodological concern for anyone evaluating alignment interventions using downstream psychological/sociological survey proxies.

arXiv · cs.CVBuildable

Beacon: Knowing When and How to Perform Agentic Visual Reasoning

Teaching AI vision models to reach for tools only when they actually need them.

When AI models tackle hard visual problems, they can be given access to external tools — like zooming into an image or running a calculation — but current approaches often use these tools clumsily, either invoking them when they're not needed (wasting time and computation) or failing to invoke them when they truly are needed (missing out on capability). Beacon studies this through two lenses: does the model correctly sense when a tool is actually necessary and use it appropriately, and does using the tool genuinely help solve problems it couldn't solve with just reasoning, without introducing new mistakes on problems it could already handle alone. The goal isn't to build a flashier tool-using AI, it's to make agentic visual reasoning actually more successful and efficient in practice. This matters because as multimodal AI systems get equipped with more tools, knowing when and how to use them well — not just whether they can — is what determines real-world reliability.

Technical view

Beacon frames agentic visual reasoning around two evaluation axes for multimodal LLMs' tool use: Mode Adaptiveness (whether the model recognizes when tool invocation is actually necessary versus unnecessary overhead) and Tool Effect (whether tool use extends capability on otherwise-unsolvable problems without introducing new errors on already-solvable ones). This reframes the goal of agentic visual reasoning from maximizing reasoning sophistication to maximizing task success rate under efficient, well-calibrated tool invocation. The paper conducts a comprehensive analysis (details of the resulting method/benchmark are truncated in the abstract) using these two dimensions as diagnostic criteria for MLLM tool-use policies. Practitioners designing tool-augmented visual reasoning agents could adopt MA/TE as evaluation axes to diagnose whether their agent's tool-calling policy is miscalibrated (over-calling or under-calling) rather than relying solely on aggregate accuracy.

arXiv · cs.CVBuildable

VAD: Attributing Visual Evidence for Target Reconstruction in Multimodal On-Policy Distillation

Teaches an AI student by showing it exactly which corrections its teacher made because of what it *saw*.

When a powerful AI (with access to images or extra info) tutors a smaller 'student' AI, it corrects the student's word-by-word guesses. But those corrections are a tangled mix of things: sometimes the teacher is correcting based on visual evidence, sometimes just because of language habits or its own quirks. VAD figures out which part of each correction actually came from looking at the picture, by testing the teacher twice on the same text — once with the image and once without — and seeing how much its confidence shifts. That shift becomes a clean signal for 'this token change was really about the visual evidence,' so the student can be trained on that signal specifically. This should make vision-language distillation more precise and less prone to copying the teacher's irrelevant biases.

Technical view

VAD targets the source-mixing problem in multimodal on-policy distillation, where next-token corrections from a privileged-view teacher conflate visual grounding with linguistic priors and teacher-specific artifacts. At each student-generated prefix it runs a counterfactual: evaluate the same fixed teacher with relevant visual evidence present versus ablated, and take the change in centered log-probabilities as ut, a signed per-token estimate of visual attributability. This isolated signal is then used to reconstruct distillation targets that emphasize genuinely evidence-supported corrections, giving a cleaner training signal than raw teacher logits for OPD pipelines.

arXiv · cs.CVBuildable

MixFrag: Fragility-Guided Mixed-Precision Post-Training Quantization for Vision Transformers

Not every part of a vision AI deserves the same number-crunching precision — this method figures out which parts are fragile.

Vision Transformers are powerful image AIs, but running them on phones or small devices means shrinking their numbers down to fewer bits (quantization) to save memory and speed. The problem is that most methods squeeze every part of the model down by the same amount, even though some layers break easily under this compression while others barely notice. MixFrag first measures how 'fragile' each component is by comparing its output before and after compression using a small sample of data, then cleverly decides how many bits to give each part so the most fragile pieces keep more precision while the sturdy ones get squeezed harder. This is framed as a classic resource-allocation puzzle (like packing a knapsack) to hit an overall size budget efficiently. The payoff is smaller, faster vision models that lose much less accuracy than uniform compression.

Technical view

MixFrag is a mixed-precision post-training quantization (PTQ) framework for ViTs that replaces uniform bit-width assignment with component-level fragility estimation. Fragility is quantified via KL divergence between full-precision and isolated quantized output distributions on a small calibration set, capturing heterogeneous sensitivity across transformer components (e.g., attention vs. MLP blocks). Bit allocation is then formulated as a Multiple-Choice Knapsack Problem (MCKP) to optimally assign per-layer precision under a global bit-budget constraint, solved without retraining. Results on ImageNet-1K across multiple ViT variants show this fragility-aware allocation outperforms uniform-bitwidth PTQ baselines at matched compression ratios.

arXiv · cs.LGConceptual

$β$-OPSD: Deriving with Policy Optimization, Training with Self-Distillation

There's a hidden dial in AI self-teaching that everyone had accidentally set to a fixed, maybe-not-optimal value.

When a reasoning AI improves itself by distilling knowledge from a stronger 'privileged' version of itself, this process is known to be finicky and hard to tune. The researchers realized that this standard method is actually just one specific setting of a more general formula, where a parameter called β controls how tightly the student AI must stay close to its own baseline behavior versus how much it should chase the teacher's guidance. By treating β as an adjustable knob instead of a fixed default, they get a whole family of training strategies, and they mathematically work out what the 'ideal' resulting AI looks like — a blend between the student's original self and the teacher. This reframing turns a brittle, trial-and-error process into something more principled and tunable, which should make self-improving reasoning models easier to train reliably.

Technical view

The paper shows vanilla on-policy self-distillation (OPSD) corresponds to β=1 in a broader policy-optimization family where β weights the KL penalty anchoring the student to a reference policy, versus pursuing privileged teacher guidance. Generalizing to β-OPSD, they derive the optimal policy in closed form as a geometric interpolation between the reference policy and the privileged teacher distribution. Since directly optimizing this objective via RL would be costly and high-variance, they instead propose a more tractable training procedure (described further in the omitted text) that approximates the derived optimal policy. This gives practitioners a principled, tunable regularization axis (β) for stabilizing self-distillation of reasoning LLMs instead of ad hoc engineering fixes.

arXiv · cs.CVBuildable

ROAD: Reciprocal-Objective Alignment of Discriminative Semantics for 3D Shape Generation

Instead of teaching an AI 3D shapes from zero, this borrows what a 'shape-recognizing' AI already knows.

Generating realistic 3D objects with AI usually means training huge models from scratch on tons of data, which is extremely expensive. But there's a separate class of AI models that are really good at recognizing and understanding 3D shapes (discriminative models), even though they don't generate anything — they just already 'get' 3D structure. ROAD is a way to transplant that existing understanding into a shape-generating AI (a diffusion model), so the generator doesn't have to relearn 3D geometry from nothing. The tricky part is that the two types of models represent shapes very differently internally, so ROAD uses a matching strategy that aligns both the big-picture meaning and the fine structural details between them. The result is 3D generation that's cheaper to train while still producing high-quality shapes.

Technical view

ROAD transfers priors from discriminative 3D foundation models into diffusion transformers for 3D shape generation, aiming to cut training cost versus scaling generative capacity and data alone. It addresses semantic-structural heterogeneity between generative and discriminative latent spaces via a reciprocal-objective alignment strategy combining 'Holistic Semantic Condensing' (global semantic coherence) and a structural optimization component (truncated in the abstract) for fine-grained geometric consistency. This is essentially a distillation/alignment recipe bridging discriminative representation learning and generative diffusion training for 3D assets. Practitioners working on 3D diffusion transformers could apply this alignment loss to warm-start generative training from existing discriminative 3D encoders, reducing compute versus from-scratch training.

arXiv · cs.AIBuildable

DualG-MRAG: Decoupling Macro-Reasoning and Micro-Matching for Multimodal Retrieval-Augmented Generation

A smarter search-and-answer AI splits 'big picture reasoning' from 'exact detail matching' instead of mashing them together.

Systems that answer complex questions by retrieving relevant text and images (multimodal RAG) often stumble on questions requiring several reasoning steps across different documents and formats. Some methods try building a knowledge graph to capture relationships, but there's a catch: including detailed visual features makes the graph huge and noisy, while simplifying it loses important specific evidence. DualG-MRAG solves this by keeping two separate graphs — one for high-level reasoning about how pieces of information connect, and one for precise, fine-grained matching of specific evidence — so each can do its job without interfering with the other. This decoupling means the system can reason broadly about a question while still pulling exact, correct details when needed. It's aimed at making AI question-answering over mixed text-and-image sources more accurate on hard, multi-step questions.

Technical view

DualG-MRAG addresses the granularity dilemma in graph-enhanced multimodal RAG: fine-grained visual features cause graph explosion and retrieval noise, while coarse representations discard critical local evidence. It introduces a dual-tier architecture decoupling a Macro-reasoning Graph, which handles global structural/cross-document relationship reasoning, from a Micro-matching Graph, which handles fine-grained instance-level evidence matching, isolating noise sources by design. This targets multi-hop multimodal QA where prior instance-level matching or single-graph approaches fail to capture explicit cross-modal, cross-document relationships. Implementers building multimodal RAG pipelines could adopt this two-graph separation as a retrieval-stage architecture pattern rather than a single unified knowledge graph.

arXiv · cs.CLRunnable

Sample More, Reflect Less: Self-Refine and Reflexion Lose to Repeated Sampling at Equal Token Cost, from 1.5B to 7B

Fancy AI self-critique tricks lose to just asking the same question over and over, once you count the tokens fairly.

There's a family of techniques where an AI tries to improve its answers by critiquing itself, reflecting on mistakes, debating with copies of itself, or picking its best attempt — all of which involve generating a lot more text than a single straightforward answer. The catch is that generating more text tends to boost accuracy on its own, regardless of whether the clever technique itself is any good, so past comparisons that ignored this were misleading. This paper redoes the comparison fairly: it counts every single token these methods use (including all the extra reflecting and debating) and compares them against a dead-simple approach of just asking the question many times and going with the most common answer, at the exact same token budget. Across seven methods, three AI model sizes, and two math tests, they find the fancy self-reflection tricks mostly lose to plain repeated sampling. This suggests a lot of the perceived cleverness of these techniques was really just 'spending more compute,' not genuine reasoning improvement.

Technical view

The paper is a controlled replication and extension of Wang et al. (2024)'s finding that self-consistency-style repeated sampling can outperform self-refine/reflexion-style methods at equal compute, but adds confidence intervals and significance testing that the original lacked. They evaluate seven inference-time methods (self-refine, reflexion, best-of-n, debate, etc.) against repeated sampling with majority voting, on open models at 1.5B, 3B, and 7B parameters across two math benchmarks (150 questions each), counting every generated token including critique/reflection/debate/checking overhead as the fairness metric. The design isolates method quality from raw token expenditure, letting practitioners judge whether a given inference-time scaffolding technique is worth its complexity versus simply increasing sample count. This is directly actionable for anyone choosing an inference-time compute strategy: the result argues for defaulting to repeated sampling as a strong, simple baseline before adopting more elaborate self-reflection pipelines.

arXiv · cs.GTConceptual

Algorithms for Structured Elections under Thiele Voting Rules

Figuring out the 'fairest' committee from votes is hard in general, but easy if voters line up in a row.

When a group of voters each approve a set of candidates and you need to pick a winning committee, there are various voting rules (Thiele rules) that try to balance overall satisfaction fairly, but computing the actual best committee under these rules can be extremely hard computationally in general. This paper studies how the pattern of who-approves-what among voters affects that difficulty — specifically looking at what happens when voters can be lined up in an order such that everyone who approves a given candidate forms one unbroken stretch of that line (the 'Voter Interval' structure). They show that under this natural structural assumption, efficient algorithms exist for finding the optimal committee under Proportional Approval Voting and other Thiele rules, even though the general problem is intractable. This kind of result matters for designing real-world voting and resource-allocation systems where ballot patterns often do have this kind of natural structure, letting us compute fair outcomes quickly instead of relying on approximations.

Technical view

The paper studies winner determination for Thiele voting rules (a parameterized family of approval-based committee election rules including PAV) under the Voter Interval (VI) domain restriction, where voters can be ordered so each candidate's approval set forms a contiguous interval. They characterize structural constraints on optimal committees induced by the approval-ballot dependency structure between candidates, and leverage this to design fixed-parameter tractable (FPT) algorithms for PAV and other Thiele rules restricted to the VI domain — a problem that is NP-hard/intractable in the unrestricted case. This contributes to the algorithmic social choice literature on exploiting single-peaked-like or interval structure in preference domains to escape general-case hardness. Researchers in computational social choice could build on these FPT results to identify further tractable ballot-structure restrictions or implement exact solvers for VI-structured elections.

arXiv · cs.AIConceptual

Rethinking Inference-Time Scaling in Local Computer-Use Agents: Failure Modes and Compute Tradeoffs

Giving AI agents more 'thinking time' on your own laptop barely helps — and can backfire.

Computer-use agents are AI programs that control a computer's mouse and keyboard to complete tasks, and running them locally (on your own device rather than a distant server) is appealing for privacy and cost. Researchers tested whether giving these local agents more computation time to think — like letting them reflect longer, replan, or try multiple attempts — actually makes them better at their jobs. They tried several ways of adding extra 'thinking': recalling more history, planning over more steps, breaking tasks into structured pieces, or running several attempts in parallel. The surprising finding is that more computation mostly gives diminishing returns and even changes what kinds of mistakes the agent makes, rather than simply making it more reliable. This matters because it tells developers that just throwing more compute at small on-device AI models isn't a free lunch — smarter strategies are needed.

Technical view

The study benchmarks Qwen3-VL-8B/30B-A3B, UI-TARS-1.5-7B, and OpenCUA-7B on OSWorld, systematically varying inference-time scaling along contextual (history), temporal (deliberation depth), structural (planning decomposition), and parallel (sampling/voting) axes. Results show diminishing accuracy gains with added compute and qualitative shifts in failure modes rather than uniform improvement; contextual scaling specifically improves trajectory stability via historical grounding. Practitioners building local CUAs should treat inference-time scaling as a tunable tradeoff against hardware budget rather than a default lever, and should profile which failure modes each scaling axis introduces before deploying.

arXiv · cs.CVBuildable

Finding Change in Satellite Archives from Text: How to Combine Before-and-After Images Efficiently

Teaching computers to spot 'a new building appeared' by comparing before/after satellite photos, fast.

Imagine searching a huge archive of satellite photo pairs — one taken before and one after some point in time — for the ones where a specific change happened, like a new building going up, just by typing a description in plain English. The key ingredient is a 'fusion module,' a piece of software that merges the before-and-after images together so the system can judge how well they match your text description. Because this module has to run on every single candidate pair in the archive, how fast it works determines how fast (and expensive) the whole search is. The researchers compared eight different ways of building this fusion module, including a new method they invented called Temporal Bottleneck Fusion, testing them all under identical conditions to find the best balance of speed and accuracy.

Technical view

Using a frozen CLIP image encoder and a fixed training recipe as controls, the authors benchmark eight fusion architectures spanning attention-based, state-space model (Mamba) based, and learned-compression approaches (their proposed Temporal Bottleneck Fusion, TBF) on bi-temporal change retrieval over LEVIR-CC and Dubai-CC-style benchmarks. The controlled setup isolates the fusion module's contribution to retrieval quality versus query-time latency, since this module runs per candidate pair at search time. This gives practitioners a like-for-like efficiency/accuracy comparison for choosing or designing fusion modules in large-scale change-retrieval pipelines.

arXiv · cs.CLBuildable

Frontis-MA1: Training an AI4AI Model towards Recursive Self-Improvement in Machine Learning Engineering

An AI trained to get better at building AI — by practicing machine-learning engineering on itself.

This project explores 'recursive self-improvement,' the idea of an AI system that gets better specifically at the job of building other AI systems, which researchers shorthand as 'AI4AI.' They built a full toolkit called OpenMLE, including simulated environments where an AI agent can try machine-learning engineering tasks and get feedback on whether its code actually works. On top of this, they trained a 35-billion-parameter model called Frontis-MA1 to act like an autonomous ML engineer, using four basic moves — draft an idea, improve it, debug it, and combine (crossover) good ideas — much like how human engineers iterate. The model is trained on real execution feedback and tested on a standard machine-learning benchmark, aiming to show that an AI can meaningfully improve the process of engineering AI, not just individual answers.

Technical view

OpenMLE provides verifiable ML-engineering task environments with execution feedback (OpenMLE-Gym), operator-level RL training (OpenMLE-RL), and long-horizon evolutionary search (OpenMLE-Evo). Frontis-MA1 (35B) is post-trained via execution-grounded SFT and RL over four atomic program-evolution operators (Draft, Improve, Debug, Crossover), deduplicated against evaluation benchmarks, then composed into a long-horizon evolutionary search loop unifying learning and evolution. It is evaluated on MLE-Bench Lite under a 12-hour per-task compute budget, offering a reproducible operator-based framework other researchers could extend for recursive self-improvement research in ML engineering.

arXiv · stat.MLBuildable

Doubly Robust Functional Representation Learning for Longitudinal Causal Inference with Irregular Histories

Making cause-and-effect statistics work on messy, irregularly-timed medical data streams.

In medical studies, patients' health data — lab results, vital signs, sensor readings — often get recorded at random, uneven times rather than neat regular intervals, which makes it hard to answer cause-and-effect questions like 'did this treatment actually help?' Standard statistical methods that are robust to modeling errors (called 'doubly robust' methods) usually need simple, single-number summaries, but these irregular data streams don't compress easily. The researchers built a method, DR-FRL, that uses machine learning encoders to turn these messy timelines into structured mathematical representations tailored specifically for the causal question being asked, then runs a battery of checks (calibration, overlap between treatment groups, tail behavior) to verify the representation is trustworthy before drawing conclusions. This matters because it lets doctors and researchers get statistically sound answers about what treatments work, even from real-world messy patient data.

Technical view

DR-FRL is a cross-fitted estimation workflow that maps irregular functional histories (point-cloud-style measurements at unequal times) into estimand-targeted latent states via functional and temporal encoders, coupled with nuisance heads estimating outcome, treatment, and censoring functions for doubly robust estimation. Unlike standard sequence learners that optimize predictive loss without guaranteeing the efficient influence function (EIF) is stabilized, DR-FRL explicitly validates the learned state against EIF-targeted diagnostics — calibration, overlap, tail behavior, and ablations — before it's used in the estimating equation. This gives causal inference practitioners a template for building representation-learning-based doubly robust estimators for longitudinal data without relying on hand-crafted scalar summaries.

arXiv · cs.CVBuildable

MIND: Multimodal Intent-Driven Network via Diffusion Transformers for Medical Image Fusion

AI that fuses medical scans the way a doctor would, guided by what the diagnosis is actually looking for.

When doctors combine different types of medical images — like an MRI and a PET scan — to get a fuller diagnostic picture, current AI methods apply the same blending rules everywhere, ignoring what the doctor is actually trying to diagnose or where the disease actually is. MIND fixes this by first using a medical language AI (BioMedGPT) to read the images and generate a description of the diagnostic intent — essentially, what a doctor would be looking for — and then uses that description to guide a powerful image-generation AI (a diffusion transformer) in how it merges the images. It also solves a technical wrinkle where converting images into a sequence format for these AI models loses track of spatial layout, by adding a special module that reinjects that spatial information. The goal is fused medical images that highlight exactly the pathological details a doctor needs to see.

Technical view

MIND combines a vision-language model (BioMedGPT) that generates intent-driven textual descriptions of diagnostic goals and pathology from source images, using these as conditioning signals for a Diffusion Transformer (DiT)-based fusion network. To counteract the loss of 2D spatial continuity inherent in flattening images to 1D token sequences for DiTs, the authors introduce a Multi-scale Latent Adapter that extracts spatial features pre-serialization and injects them back via dimension-aligned fusion. This text-guided, pathology-aware conditioning approach offers a template for practitioners wanting to steer generative fusion models toward clinically relevant, task-specific outputs rather than generic global fusion rules.

arXiv · cs.LGBuildable

APO: Unsupervised Atomic Policy Optimization for 3D Structure Prediction of Atomic Systems

Predicting molecule and crystal shapes without needing costly lab-verified 'right answers' to learn from.

Scientists want AI to predict the 3D shapes of molecules, crystals, and proteins because that's crucial for designing new drugs and materials, but the leading AI methods need real experimentally-measured structures to learn from as a kind of answer key — and getting those measurements for brand-new materials is extremely expensive and slow. APO gets around this by training the AI purely on its own internal consistency and preferences, without any ground-truth answer key, using an approach adapted from a reinforcement learning technique. It rewards the model in two ways: for confidently reinforcing the structural patterns it already tends to favor, and for another signal that helps refine those predictions. This unsupervised approach could unlock structure prediction for entirely new, unmeasured materials where no answer key exists yet.

Technical view

APO adapts group-relative policy optimization (GRPO), typically used for LLM alignment, to 3D atomic structure prediction, removing the need for supervised preference learning against ground-truth coordinates (as required by prior flow-matching approaches like FlowDPO). It uses a dual-reward mechanism: one reward reinforces the model's dominant latent structural modes identified via eigen-decomposition of sample similarity, paired with a second complementary reward (details truncated in the abstract) to refine structural accuracy. This offers a path for structure-prediction practitioners to fine-tune flow-matching or diffusion-based structure generators in data-scarce regimes — novel crystal phases or de novo proteins — without requiring experimentally labeled reference structures.

arXiv · cs.CVBuildable

ScaFE: Data-Efficient Scar Classification with LLM-Generated Clinical Feature Programs

An LLM writes auditable measurement code instead of just eyeballing scar photos itself.

Telling apart two similar-looking types of scars (keloids versus hypertrophic scars) from photos is tricky for AI because there's limited labeled medical data and photos vary a lot between hospitals. Sending patient photos to a cloud-based AI to get a diagnosis also risks violating hospital data-privacy rules, and its decisions are hard to double-check or reproduce. ScaFE sidesteps both problems: instead of asking an AI to look at a photo and just guess the diagnosis, it has a language model research clinical knowledge online and write actual computer programs that measure specific, visible scar features (like color or shape) in a transparent, rule-based way. These programs run locally on the hospital's own machines, and only summary statistics and feature-importance explanations leave that environment, keeping patient data private while making the diagnostic reasoning auditable.

Technical view

ScaFE has a web-enabled LLM retrieve clinical literature and synthesize deterministic, executable 'feature programs' that quantify visually assessable scar attributes (rather than performing end-to-end image classification or VLM-based diagnosis), which run in a restricted local execution environment. Only aggregate validation statistics and feature-level SHAP summaries are needed for model refinement, keeping raw images and predictions on-premise for data-governance compliance. This approach lets practitioners build small-data, interpretable, hospital-deployable classifiers where each decision traces back to auditable, human-readable feature-extraction code rather than opaque model weights.

arXiv · cs.CVBuildable

MarkushGlyph and OCSRGlyph: Improved Chemical Structure Recognition

AI now reads messy chemistry diagrams from patents and turns them into searchable molecule codes.

Chemical structures in patents and papers are often just images, but for search engines and databases (or for training other AI models) they need to become text-based codes describing the molecule. That's easy-ish for a single, fully-specified molecule but much harder for 'Markush' structures — diagrams in patents that represent an entire family of related molecules with variable parts. This work treats both jobs as 'translate the image into text,' introducing OCSRGlyph (which reads single molecules and pays special attention to their 3D shape, or stereochemistry) and MarkushGlyph (which reads a whole complex family-diagram at once). The payoff is unlocking huge amounts of chemical knowledge currently trapped as images in patents, useful for drug discovery and chemical databases.

Technical view

Both tasks are framed as image-to-text translation using vision-language models, generating line notations (e.g., SMILES-style strings) directly from raster images. OCSRGlyph advances state-of-the-art OCSR accuracy by explicitly modeling stereochemistry in the generation objective, an area prior OCSR systems often got wrong. MarkushGlyph departs from typical segment-then-recognize pipelines by reading the entire Markush structure image holistically in one pass rather than decomposing it into substructures. This is directly useful for practitioners building patent-mining or cheminformatics training-data pipelines who need robust image-to-SMILES/Markush extraction.

arXiv · cs.CLConceptual

AI systems and the reproduction of (standard) language ideologies in World Englishes

Chatbots quietly decide whose English counts as 'proper' — and it's rarely the Global South's.

Sociolinguists have long asked who gets to decide what 'correct' English is, and this paper argues AI systems are now baking that judgment into technology. 'Standard language ideology' means favoring the English of dominant, mostly white native-speaking countries (the 'Inner Circle') while treating other varieties — like Nigerian, Indian, or Filipino English — as wrong or suspicious, even though they're just as legitimate. The paper studies real examples, like the online panic over the word 'delve' being used as a signal to accuse writers of secretly being AI, which unfairly targeted African English speakers who use the word naturally. It matters because this bias isn't neutral — it can affect whose writing gets flagged as fake, whose voice gets 'corrected,' and who gets excluded from being seen as a legitimate English speaker in an AI-saturated world.

Technical view

The paper conducts a discourse and case-study analysis spanning training data composition, model design and evaluation benchmarks, human feedback/RLHF loops, and public/media reception, arguing ideology gets embedded at each pipeline stage. Its central case study is the 'delve' controversy, where a lexical marker common in non-Inner-Circle (particularly Nigerian/African) English got used as an AI-detection heuristic, disproportionately flagging non-native-coded writers as suspect. The analysis implies that grammaticality/naturalness benchmarks and annotator pools skew toward Inner Circle norms, systematically penalizing other varieties in both model outputs and downstream detection tools. Relevant to NLP practitioners designing dialect-fair evaluation sets, annotator diversity protocols, and AI-text-detection systems that shouldn't conflate 'unusual word choice' with 'AI-generated.'

arXiv · cs.AIBuildable

MANTA: Multi-Agent Network Topology Adaptation for Self-Evolving Multi-Agent Systems

AI agent teams that redraw their own org chart mid-task when the plan stops working.

When several AI 'agents' work together on a hard problem, they usually communicate through a fixed structure decided in advance — who talks to whom, who checks whose work. MANTA lets that structure change while the task is actually running: it starts with a communication setup suited to the task type, then watches how the collaboration is going and, if things start breaking down, reshuffles roles, connections, the order agents act in, or who can see what. This matters because a rigid team structure can become a bottleneck once a task turns out harder (or easier) than expected, so letting the team reorganize itself on the fly should make these AI systems more robust and efficient.

Technical view

MANTA initializes a task-conditioned communication topology from prior structural experience, then during execution monitors collaboration traces (message/validation outcomes) and applies bounded structural updates — altering agent roles, communication edges, execution order, information visibility, and validation pathways — while holding the task interface and agent budget fixed. This positions topology as a dynamic, online-adapted variable rather than a fixed design choice or purely offline-optimized target, distinguishing it from static multi-agent orchestration frameworks. Practitioners building agent orchestration systems (AutoGen/CrewAI-style) could use the monitoring-plus-bounded-update mechanism as a template for making any fixed agent graph self-repairing at inference time.

arXiv · cs.CVBuildable

What to Remove, What to Preserve: Dual-Ambiguity Rectification for All-in-One Image Restoration

An AI photo-fixer that first figures out exactly what kind of damage it's looking at before touching the picture.

'All-in-one' image restoration means one AI model that can fix many kinds of damage — noise, blur, rain streaks, low light — instead of needing a separate model for each. The problem is these models often confuse 'this is damage' signals with 'this is real picture content,' so they end up erasing genuine detail or leaving weird artifacts behind. DAR-Net tackles this by building a structured description of the damage type (like mixing a known set of 'damage recipes' in the right proportions) and using that to generate targeted instructions for exactly which parts of the image and which visual channels need fixing, keeping 'what's wrong' cleanly separate from 'what's actually there.' The goal is sharper, cleaner restoration across many damage types without the usual mix-ups.

Technical view

The Degradation Archetype Representation (DAR) module models degradation as a simplex-constrained mixture of learned archetypes — essentially soft-clustering the input onto a basis of canonical degradation types to form a structured degradation state. This state feeds a Semantic Ambiguity Rectification (SeAR) module that generates degradation-aware prompts for channel-wise feature modulation, explicitly disentangling degradation cues from scene semantics rather than mixing them in a shared latent space as prior all-in-one methods do. The framing suggests a companion mechanism handles the paper's 'spatial ambiguity' (localizing where restoration should act) though details are cut off. Practitioners building unified restoration backbones could adopt the archetype-mixture conditioning as a drop-in alternative to shared-latent degradation embeddings.

arXiv · cs.LGBuildable

Same Graph Cross-Task Transfer in GNNs: Protocols and Predictors

Does teaching a graph AI to label nodes also help it guess missing connections? Usually — but not the reverse.

Graphs, like social networks, support different prediction tasks on the same structure: guessing a label for each node (node classification) or guessing whether two nodes should be linked (link prediction). It seems obvious that training on one task should help with the other since it's the same graph, but past studies testing this used inconsistent, leaky evaluation setups that made the conclusions unreliable. This paper builds a fair testing protocol — fixed data splits, hiding the exact edges being tested from the model during training, and consistent 'negative examples' for comparison — then tests it across standard graph AI architectures. They find that going from node-labeling to link-prediction reliably helps when connected nodes tend to be similar to each other, but going the other way, from link-prediction to node-labeling, is unreliable and can even make things worse.

Technical view

The paper formalizes same-graph NC-LP transfer and introduces a leakage-free evaluation protocol: fixed node/edge splits, message passing restricted to a graph excluding evaluated edges, and fixed negative sampling for LP, tested across GCN, GraphSAGE, and GPS backbones. Key finding: NC→LP transfer is consistently beneficial on homophilic graphs (where connected nodes share labels/features), while LP→NC transfer is direction-fragile and can degrade accuracy under naive representation reuse, becoming reliably positive only under certain conditions. This gives practitioners both a reusable leakage-free benchmarking protocol and a predictive heuristic (homophily + transfer direction) for deciding when to share representations between NC and LP heads in multi-task GNN systems.

arXiv · cs.GTBuildable

Agents That Certify Their Own Exploits: Confidence-Scheduled Restricted Responses for Safe Opponent Exploitation

A poker AI that only exploits an opponent's weakness once it can mathematically prove the weakness is real.

In head-to-head games with hidden information, like poker, playing a perfectly balanced strategy (a 'Nash equilibrium') is safe but leaves value on the table against a weak opponent — yet fully attacking a guessed weakness is risky, because if the read is wrong, the AI becomes exploitable itself. This method has the agent track the opponent's actual behavior across many hands using statistics that stay valid no matter when you check them, and it only starts exploiting a specific tendency once the evidence clearly shows that tendency deviates from balanced play, scaling how aggressively it exploits to how confident it is. The point is squeezing more value out of a weak opponent's real mistakes without the danger of overreacting to noise and getting punished for it.

Technical view

CS-RNR (budget-constrained confidence-scheduled restricted responses) tracks pooled opponent action frequencies with anytime-valid confidence sequences — statistical intervals that remain valid under continuous monitoring without inflating false-positive rates — and flags a frequency as exploitable only once its confidence interval separates from the equilibrium reference. Confirmed deviations define a conservative restricted-best-response set, and the agent computes and certifies a safety bound on the exact strategy it deploys, rather than relying on a fixed heuristic release threshold. This builds on the restricted Nash response (RNR) literature and is directly applicable to poker or other two-player zero-sum agents wanting principled, self-audited online opponent exploitation with worst-case exploitability guarantees.

arXiv · cs.CVBuildable

Beyond Frame Selection: Generative Latent Evidence Aggregation for Long-Video Understanding

Teaching video AI to connect the dots between distant frames, not just pick the best ones.

When an AI watches a long video to answer a question, it usually just grabs a handful of 'important' frames and looks at them separately. The problem is that the real answer often depends on combining clues scattered across different moments — like noticing someone picks up a key early on and uses it much later. This paper's system, GenEvA, adds a step that actively fuses information across the selected frames into a compact combined 'story' before the AI answers, using the question itself to guide which frames matter and how they relate. The result is an AI that reasons across time rather than just glancing at isolated snapshots, which should make it much better at answering questions about long, complex videos.

Technical view

GenEvA inserts a query-conditioned latent aggregation stage between frame/token selection and answer generation for long-video QA, using a distribution over frames (weighted by relevance to the query) to guide a generative module that fuses frame-specific representations into compact cross-frame latent evidence. This addresses the failure mode where compact evidence sets retain relevant content but leave cross-frame integration to the downstream LLM, which often fails to combine complementary cues implicitly. Practitioners building long-video QA pipelines could adopt this as a drop-in module between existing frame-selection methods and the generation backbone to improve multi-moment reasoning without increasing token budget.

arXiv · cs.CLConceptual

Creative Transformation in Literary Texts: Modelling Change Across Representational Levels

A math-flavored theory of literary borrowing: what writers copy, and what they dare to change.

This paper asks: when one writer clearly draws on an earlier work, what exactly gets copied and what gets creatively transformed? Drawing on old ideas about imitation from sociologists Gabriel Tarde and James Mark Baldwin, the authors build a framework that compares two texts across several layers at once — word choice, meaning, underlying concepts, structure, and overall story arc. Using computational similarity measures, they check, for real documented cases of literary influence, which of these layers stay close to the original and which diverge. This gives a numeric, testable way to describe creativity as 'selective transformation' rather than either pure copying or pure invention, useful for literary historians and computational humanities scholars alike.

Technical view

The authors formalize literary influence as a multi-level comparison problem, computing directional, control-calibrated alignment/similarity scores between source and derivative texts across five representational levels (lexical, semantic, conceptual, structural, narrative). Applied to historically attested literary relationships, the method yields 'transformation profiles' showing that different text pairs preserve fidelity at different levels (e.g., structural retention with conceptual divergence). This offers a reusable, quantitative pipeline for computational literary studies to characterize influence and creativity beyond binary originality judgments, and could be extended with additional levels or applied to cross-lingual or cross-media adaptation studies.

arXiv · cs.CVBuildable

RefCaptioner: Multi-Reference Image-Grounded Video Captioning

An AI that captions videos while pointing to exactly which reference photo backs up each claim.

Normal video-captioning AIs write a description of a video but can't show you proof for specific details — like which reference photo confirms 'that's the red car from image 2.' This paper introduces a new task and system, RefCaptioner, that generates video captions while explicitly linking each phrase to one or more supplied reference images, rejecting irrelevant 'distractor' images and staying consistent across many references. It's trained in two stages: first on a large mixed dataset, then fine-tuned with a reward-based method that specifically teaches it to pick the right reference, bind phrases correctly, and ignore wrong images. The team also built a huge new dataset (20,000 videos, 171,354 reference images) and a benchmark to test this, aiming for video descriptions that are more factual and verifiable.

Technical view

RefCaptioner tackles multi-reference image-grounded video captioning via a two-stage post-training pipeline: mixed-data supervised fine-tuning followed by Hierarchical Coverage-Discounted GRPO, a reinforcement-learning scheme that jointly optimizes reference selection, phrase-level grounding, distractor rejection, and cross-reference consistency while preserving general captioning quality. It's trained/evaluated on a purpose-built corpus of 20K videos and 171K reference images, and evaluated on the new MRVBench benchmark covering both real and AI-generated video factuality and grounding. This provides a concrete recipe (SFT + custom GRPO reward shaping) that practitioners can adapt for other grounded-generation tasks requiring fine-grained attribution to external evidence sources.

arXiv · cs.CLConceptual

Generative AI and linguistic diversity in academic writing and publishing: Perspectives from World Englishes

Five linguists debate whether AI writing tools help or erase the world's many Englishes in research papers.

As AI writing tools become common in academic publishing, a big question emerges: do they help scholars who don't write in 'standard' English get published more easily, or do they quietly flatten all the rich variety of World Englishes into one homogenized style? This article is a structured conversation among five sociolinguists who specialize in studying different varieties of English around the globe. They discuss whether AI democratizes academic writing by lowering the language barrier, or whether it reinforces dominance of a narrow 'standard' English and erases nuance from non-native or regional varieties. The piece raises themes of fairness, who controls the writing process, and what responsibility universities and journals bear as these tools spread.

Technical view

This is a structured scholarly dialogue (not an empirical study) among five World Englishes researchers, organized around five guiding questions about GenAI's effects on academic writing and publishing norms. It surfaces tensions between GenAI's potential to lower entry barriers for multilingual/non-native English scholars and its tendency to normalize dominant (typically Inner Circle) English varieties, discussing implications for linguistic justice, author agency, and institutional policy. Readers building AI writing-assistance tools or setting journal AI-use policies can use this as a framework for anticipating equity trade-offs rather than a source of quantitative findings.

arXiv · cs.AIRunnable

InfoOps Bench: A live information operations safety benchmark

A live scorecard testing whether top AI chatbots can be tricked into spreading state propaganda.

Governments like Russia, China, and Iran run 'information operations' — coordinated efforts to spread propaganda and disinformation online. This paper builds a constantly updated benchmark that tests whether popular AI language models can be manipulated into helping spread these state-backed claims, drawing on a live monitoring system tracking over 2,100 real information operations. They tested 17 different AI models from 8 companies, asking each in four different ways, and measured 'integrity scores' — the percentage of times each model refused to help. The scores varied wildly, from just 8.8% refusal up to 94.5%, showing most models can be manipulated to some degree and that safety varies enormously between providers.

Technical view

InfoOps Bench is a live, continuously refreshed safety benchmark built from a monitoring pipeline tracking 2,100+ real Russian, Chinese, and Iranian state-backed information operations, designed to resist saturation/gaming by updating weekly with fresh claims (companion site: pattrn.ai/research/infoopsbench). The authors evaluate 17 frontier models across 8 providers under four prompt framings, measuring an 'integrity score' as refusal rate; scores range from 8.8% to 94.5%, an 85.7-point spread not fully explained by model capability alone, implying divergent safety training around propaganda-adjacent requests. Practitioners doing AI safety red-teaming or model selection for content-moderation-sensitive deployments can use this benchmark as an ongoing, non-static eval rather than a one-time static test set.

arXiv · cs.IRBuildable

TCA-SIR: Learning Target-Conditioned Abstractions for Scientific Inspiration Retrieval

Teaching AI to find scientific inspiration by extracting the reusable 'trick,' not just similar topics.

When scientists look for inspiration to solve a hard problem, sometimes the best ideas come from a totally different field that shares no obvious topic overlap but uses a similar underlying trick. Current AI tools for finding scientific inspiration just search for papers about similar subjects, missing these 'remote' but powerful analogies. This paper proposes a new approach, TCA-SIR, that mimics how humans actually do this: it pulls out the abstract, reusable 'principle' behind a candidate paper — tailored specifically to the problem you're trying to solve — rather than just matching keywords or topics. Tested on a research benchmark, it does a better job than older methods at surfacing genuinely useful cross-domain inspirations for generating new scientific hypotheses.

Technical view

TCA-SIR reframes Scientific Inspiration Retrieval as target-conditioned abstraction: rather than ranking candidate papers by topical/embedding similarity to a target problem, it learns to generate a transferable abstract principle extracted from each candidate specifically conditioned on the target, then uses representations of these generated abstractions to predict transferability/relevance. This directly targets the 'remote inspiration' problem where topical similarity fails to capture cross-domain conceptual transfer. On ResearchBench it outperforms prior similarity-ranking-based SIR baselines, suggesting a template — generate-then-score conditioned abstractions rather than embed-and-rank — that could generalize to other analogy-retrieval or hypothesis-generation pipelines in AI-for-Science systems.

arXiv · cs.LGConceptual

The Role of Causality in Algorithmic Recourse

Why telling people 'change X to get a loan' can backfire if X doesn't actually make them more creditworthy.

When an algorithm denies you a loan, 'algorithmic recourse' tools suggest changes you could make to get approved next time — like 'increase your income' or 'pay down debt.' But most of these tools only care about flipping the model's decision, not whether the suggested change genuinely makes you a better borrower or just games the system's specific quirks. This paper shows that ignoring real cause-and-effect relationships between features can backfire: people follow the advice, the model gets retrained on this gamed behavior, and the whole system becomes less accurate and the advice stops working. The authors build a framework that models how recourse actions actually ripple through real-world cause-effect relationships (a 'structural causal model'), aiming for advice that leads to true improvement rather than exploitable loopholes.

Technical view

The paper formalizes a causal performative framework for algorithmic recourse, modeling recourse actions as interventions propagating through a structural causal model that captures feature interdependencies and their causal effect on the true (unobserved) label, rather than treating recourse as pure counterfactual explanation for flipping a classifier's output. This exposes a performativity failure mode: recourse policies optimized only for prediction-flipping induce behavioral responses that degrade accuracy over retraining cycles and become self-defeating. The resulting optimization is non-convex, and the framework provides a basis for designing recourse algorithms constrained to causally-effective interventions, relevant to practitioners deploying recourse in lending/credit scoring who need policies robust to model retraining and strategic response.

arXiv · cs.CLRunnable

Beyond Sentiment: Structured Information Extraction from Financial News

Financial news carries way more predictive signal than 'positive or negative' — this paper mines six hidden dimensions.

Most stock-prediction AI reduces a whole news article down to one number: how positive or negative it sounds. This paper argues that's throwing away useful information, because news also encodes things like what kind of event happened, how big its impact is, over what time frame it matters, and how confident the reporting is. The researchers use a large language model (LLaMA-3.1-70B) to automatically pull out six such dimensions from over 41,000 real news-stock pairs, then test how well each dimension predicts stock movement. They find that sentiment alone is a messy, nonlinear signal — it works okay with complex models but poorly with simple ones — suggesting that combining these extra structured dimensions could make stock prediction from news meaningfully more reliable.

Technical view

The authors move beyond scalar sentiment scores for news-driven stock prediction by using LLaMA-3.1-70B to extract six semantic dimensions (event type, impact scope, temporal horizon, semantic confidence, and others) from financial news, then evaluate predictive value on 41,618 news-stock pairs from the FNSPID dataset. A key finding is that FinBERT sentiment features are highly nonlinear predictors (F1=0.576 under nonlinear models vs. only 0.230 under linear models), demonstrating that sentiment's predictive power is model-dependent and incomplete on its own. This suggests a practical recipe for quant/NLP practitioners: augment or replace single-score sentiment pipelines with LLM-extracted structured multi-dimensional features to capture orthogonal, independently predictive signal in financial text.

arXiv · cs.LGConceptual

Stage-Replay Divergence Follows the KV Cache: Fixed-Prefix Precision Controls and Bidirectional Cache Transplantation

Debugging tools that replay an AI's 'thinking' can secretly change its answers.

Some tools try to inspect how an AI reasoning system arrived at an answer by rewinding it and replaying part of its work — but this study checks whether that replay actually behaves like the real thing. It turns out the replayed version and the live version can disagree on what comes next, and the culprit is tiny floating-point rounding differences in the AI's internal memory of past computations (called a KV cache), not a real change in reasoning. Using lower numerical precision (BF16, a compact number format) causes disagreements that vanish once higher precision (FP32) is used. The researchers then built a technique that makes the replayed and live memories match exactly, bit for bit. This matters because it means debugging or auditing tools for AI reasoning need to be built carefully or they can mislead you about what the AI 'really' did.

Technical view

KV-cache reconstruction via one-shot prefill diverges from a retained live cache at BF16 precision due to floating-point non-associativity rather than any logical difference in computation; a fixed-prefix 2x2 design isolates construction method from numeric precision, and BF16 disagreements (166/200 differing suffixes, 20 differing correctness labels) disappear entirely under FP32 (Wilson upper bound 1.88%). The authors then engineer a token-by-token incremental bridging procedure that achieves bit-exact agreement between incremental and retained caches on 12/12 test cases. Takeaway for practitioners: interpretability or stage-replay auditing tools for LLMs must control for numeric precision or adopt bit-exact cache reconstruction to avoid attributing precision artifacts to reasoning differences.

arXiv · cs.AIBuildable

SCOPE: Supply-Chain Operations through Coupled Policies for End-to-End Coordination

One AI now plans a whole supply chain at once instead of department by department.

Running a supply chain means deciding what products go where, which warehouse supplies each store, how often to restock, and which delivery routes to use — and these choices are tangled together, since restocking often changes shipping needs, which changes route costs, which changes whether the original plan was even a good idea. Normally different teams handle these pieces separately with different tools, which causes stockouts, excess inventory sitting around, and wasted trucking. SCOPE proposes a single AI system, a 'composite policy,' that makes all these decisions together instead of in isolated silos. The goal is coordinated planning that accounts for how each choice ripples into the others, cutting waste across the whole chain.

Technical view

SCOPE frames assortment (product-location placement), source assignment, replenishment frequency, and delivery routing as coupled decisions in one composite policy architecture rather than sequential, siloed optimization stages, explicitly modeling how assortment shapes downstream demand/load, how sourcing and cadence reshape delivery requests, and how routing feasibility/cost feeds back into the value of upstream choices. The abstract is truncated before detailing the exact policy representation, but the framing implies an end-to-end trainable or jointly-optimized decision system spanning inventory and logistics layers. Practitioners in supply-chain ML could benchmark such coupled policies against siloed department-level baselines on stockout rate, inventory exposure, and transportation cost.

arXiv · cs.CVBuildable

AuricularWorld: Hierarchical Action-Guided World Modeling for Fine-Grained Auricular Structure Segmentation from CT Scans

An AI iteratively sketches and refines its guess of tiny ear-cartilage shapes hidden in CT scans.

Segmenting the ear's cartilage from a CT scan is hard: the ear is a small part of the image, its cartilage edges are irregular, and the boundary between cartilage and nearby skin is often blurry, with labels that overlap in confusing ways (some describe cartilage-plus-skin together, others cartilage alone). Instead of predicting the outline in one single pass like typical segmentation AIs, this system builds an internal 'world model' — a simulated, evolving belief about the anatomy that it refines step by step, more like a sculptor revising a shape than a camera snapping one photo. It combines features from multiple zoom levels with partially-finished guesses to kick off this iterative refinement process. This matters for applications like planning ear reconstruction surgery, where precise cartilage boundaries are critical.

Technical view

The framework embeds a deterministic recurrent state-space model (RSSM-style latent dynamics) into an encoder-decoder segmentation architecture, replacing single-pass feed-forward prediction with iterative latent refinement. Multi-scale encoder features are fused with partially decoded representations to form a 'structural observation' that seeds the latent state, which then evolves over inference steps toward a final segmentation, explicitly handling nested/overlapping labels (composite cartilage-plus-tissue regions vs. cartilage-only regions). Practitioners working on small, ambiguous-boundary anatomical structures could adapt this world-model/RSSM refinement approach as a general alternative to single-shot segmentation heads.

arXiv · cs.CVRunnable

Towards Real-Time PixOOD: Efficient Anomaly Segmentation for Autonomous Vehicles

Self-driving cars can now spot unfamiliar obstacles 20x faster, fast enough to run onboard.

Autonomous cars and trains need to notice things they've never been trained on — a fallen tree, an odd obstacle — a task called anomaly or out-of-distribution segmentation. The best existing methods for this are accurate but too slow to run on the actual limited computers inside a vehicle. This work takes PixOOD, a leading anomaly-detection method, reworks its internal scoring math to be more efficient, and compiles the whole pipeline using TensorRT (a tool that optimizes AI models to run fast on NVIDIA chips). The result runs dramatically faster on both desktop GPUs and small embedded chips used in real vehicles, making real-time safety monitoring for self-driving cars and trains practically deployable.

Technical view

The authors reformulate PixOOD's Neyman-Pearson scoring stage for computational efficiency and deploy the full pipeline via hardware-optimized TensorRT compilation, achieving 182 FPS on a desktop RTX 4060 and 75 FPS on a Jetson AGX Orin embedded platform — 20x and 18x speedups over the original baseline, respectively — targeting autonomous driving and railway domains. This provides a concrete, benchmarked template for taking accuracy-oriented OOD/anomaly segmentation models and making them real-time-deployable on embedded automotive-grade hardware. Practitioners could replicate the approach by applying similar scoring-stage reformulation plus TensorRT graph compilation to other segmentation-based safety-critical pipelines.

arXiv · cs.AIBuildable

A Fuzzy Rule-based Neuro-Symbolic Approach for Pipe Severity Prediction in Sewer Networks

An AI inspecting sewer pipes now explains its 'this pipe is bad' verdict in plain rules.

Automated sewer inspection usually feeds camera footage into an image classifier that spits out a severity score with no explanation — a 'black box.' This approach splits the job into two interpretable steps: first, a vision AI (a Swin Transformer, a type of image-recognition neural network) reads photos and identifies 14 specific defect codes, like cracks or corrosion. Then a separate, transparent decision-tree system (trained to mimic expert judgment) converts patterns of these codes into 19 simple IF-THEN rules, and 'fuzzy logic' — math for handling shades of truth rather than strict yes/no — blends the confidence of triggered rules into a final graded severity verdict. This gives inspectors a trustworthy, explainable severity rating instead of an opaque number, useful for prioritizing pipe repairs.

Technical view

The pipeline decouples perception from reasoning: a Swin Transformer performs multilabel prediction of 14 CODE degrees directly from inspection images, while a Weka J48 decision tree trained on CODE-to-severity ground truth is converted into 19 fixed IF-THEN rules. Inference combines these via fuzzy logic — t-norm activations from CODE conditions weighted by rule confidence, aggregated with corresponding s-norms — with the authors comparing Product, Łukasiewicz, and Hamacher fuzzy operator pairs for producing interpretable class evidence. This gives infrastructure-inspection practitioners a replicable neuro-symbolic template (CNN/transformer perception + decision-tree-derived symbolic rules + fuzzy aggregation) for interpretable severity scoring beyond black-box classification.

ROB

Robotics

28 new
arXiv · cs.ROConceptual★ flagship

PAC-MAN: Perception-Aware CBF-RL for Whole-Body Safety in Humanoid Dodgeball

A humanoid robot learns to dodge thrown balls using only what its head camera sees.

Teaching a walking robot to physically dodge an incoming object is hard because in the real world the robot only has its own onboard camera — it can't magically know exactly where the ball is. PAC-MAN trains such a robot for 'dodgeball,' where at deployment it perceives the ball merely as a fuzzy depth blob from a head-mounted camera. The trick: during training it gets richer safety guidance (a 'control barrier function' that tracks how close the ball is to every part of its body) plus a nudge to keep its evasive moves looking natural rather than flailing. Remarkably, the camera-only robot dodges nearly as well as an idealized version that's fed perfect ball positions, and it can even walk back to its spot and reset between throws. The key finding is that how well the robot can safely react depends on how observable the threat is to its actual sensors.

Technical view

PAC-MAN couples control-barrier-function (CBF) safety with reinforcement learning under deployment-realistic perception: the deployed policy observes only segmentation-masked depth of the ball from a head-mounted camera, while training-time CBF guidance encodes clearance to every body link and an adversarial motion prior regularizes evasive behavior. On an any-link-contact benchmark with seeded throws (single-throw and a walk-back-and-recover deployment loop), the onboard-camera policy comes within a few points of a privileged state oracle. A central result is that usable barrier structure is contingent on perceptual observability — Joint-CBF excels with accurate ball states but degrades otherwise. Practitioners get a template for perception-aware CBF-RL where safety constraints are defined over whole-body link clearances yet conditioned on realistic onboard sensing.

arXiv · cs.ROBuildable

FA-RDP: A Frequency-Adaptive Reactive Diffusion Policy for Contact-Rich Manipulation

A robot hand that thinks slow before touching, then reacts fast once it's touching.

When a robot arm tries to grab or manipulate an object, its strategy needs to change the moment it makes contact: before touching anything, there are many equally good ways to approach, but after contact, physics and force limits narrow things down and the robot needs to react instantly to what it feels. Modern robot control methods called 'diffusion policies' generate actions by gradually refining random guesses, similar to how image-generating AI works, but they run at one fixed speed throughout — which is either too slow to react well after contact, or too fast and rigid to consider multiple good options before contact. This paper's method, FA-RDP, automatically switches its own thinking speed: slower and more exploratory before touching, faster and twitchier once contact is made, using a shared model that tracks visual and force information together. The payoff is a robot that can be both flexible in its approach and responsive once it's actually handling something, which is crucial for tasks like inserting a plug or assembling parts.

Technical view

FA-RDP tackles the frequency mismatch in diffusion-based manipulation policies: low-frequency, multi-step denoising preserves pre-contact action multimodality but reacts sluggishly to force feedback, while high-frequency sampling improves reactivity post-contact at the cost of mode collapse. The method uses a shared multi-frequency visual-force Transformer that predicts actions conditioned on inferred contact phase, allowing the policy to adaptively select its inference frequency/sampling steps online rather than fixing them a priori. This effectively decouples the multimodality-preservation and reactivity requirements that previously forced a single global frequency compromise. Practitioners building contact-rich manipulation policies (insertion, assembly, contact-based grasping) could adopt this frequency-adaptive scheduling as a drop-in mechanism atop existing diffusion policy architectures that already fuse vision and force sensing.

arXiv · cs.ROBuildable

X-NavDP: Generalizing Navigation Diffusion Policy to Novel Behavior and Embodiments with Group Q-score Reweighted Matching

Training robots to navigate by letting them practice, not just copy an all-knowing planner.

Robots that learn to navigate are usually trained by imitating an 'oracle' planner that has perfect knowledge of the map — like learning to drive by copying a GPS that can see through walls. The problem is this doesn't teach the robot to improvise in messy real situations, like backing out of a dead end, using only what its own cameras and sensors can see, and it doesn't generalize to robots of different shapes and sizes. This paper adds a second training phase using reinforcement learning — trial and error with rewards — to fine-tune the navigation model, but doing this with 'diffusion' style AI models (which generate action plans by iterative refinement) is normally unstable and inefficient. The authors' new technique, GQRM, reweights and stabilizes this trial-and-error process so it actually improves the robot's real-world reactive behavior. This makes robots more adaptable to new bodies and tricky obstacles without needing new hand-labeled demonstrations for every case.

Technical view

X-NavDP post-trains a diffusion-based navigation policy (originally pretrained on oracle-planner demonstrations for a single embodiment) using a novel data-efficient RL framework called Group Q-score Reweighted Matching (GQRM). GQRM addresses the core obstacle to RL fine-tuning of diffusion policies — the intractable likelihood that destabilizes policy gradients and hampers exploration — by reweighting groups of sampled trajectories via Q-scores rather than relying on standard policy-gradient estimates. This yields more than marginal gains (the stated failure mode of prior diffusion+RL approaches) in generalizing to novel embodiments and reactive behaviors like dead-end escape and obstacle detour using only onboard local observations. Roboticists working on embodiment-agnostic navigation or diffusion-policy RL fine-tuning have a concrete alternative to standard policy-gradient or DDPO-style approaches to try.

arXiv · cs.ROBuildable

TEA-AgriVLN: Traversability Estimation Alarm for Agricultural Vision-and-Language Navigation

A farm robot that second-guesses itself when a cornfield looks walkable but might not be.

Robots navigating by following spoken or written instructions ('go past the barn to the field') have been tested mostly indoors, where it's obvious what's walkable — wood floor yes, concrete wall no. But outdoors on a farm, whether something is 'traversable' is fuzzy: a robotic dog might be able to push through unripe corn stalks, while the same path would stop a person. This paper introduces TEA, a module that looks at the camera image, estimates how traversable the terrain actually is, and raises an internal 'alarm' when the robot's planned action doesn't match that traversability estimate, prompting it to reconsider. This lets an agricultural navigation robot avoid blindly following a language instruction into a spot that's technically impassable for its own body, making outdoor robot navigation safer and more reliable.

Technical view

TEA-AgriVLN extends the AgriVLN vision-and-language navigation framework by adding a Traversability Estimation Alarm module that predicts a continuous or embodiment-conditioned traversability score from the current camera image, rather than relying on the binary indoor-style traversability assumptions baked into prior VLN-CE benchmarks like A2A. When the policy's selected low-level action conflicts with the estimated traversability, the alarm triggers a re-evaluation step in the decision-maker, effectively adding a safety/consistency check on top of the base navigation policy. This targets a specific domain gap — ambiguous, embodiment-dependent traversability in agricultural terrain versus indoor scenes — and offers a pattern (estimate-then-alarm-then-replan) that could generalize to other outdoor or unstructured VLN-CE settings. Implementers could integrate the TEA module as an auxiliary head or gating layer on existing VLN-CE policies without retraining the full pipeline from scratch.

arXiv · cs.ROConceptual

Machines that know they are aging: a framework for hardware-aware autonomous intelligence

Robots that feel their own hardware wearing out — and plan around it before they fail.

Autonomous machines like drones, rovers, or satellites are usually programmed as if their hardware stays perfect forever, but in reality batteries weaken, sensors drift out of calibration, and processors get less reliable over time. The danger is that a mission can fail not from one big breakdown but from many small degradations quietly piling up — the authors call this 'agnostic collapse,' since the machine's own AI doesn't even realize it's degraded. This paper proposes a framework where the robot's AI continuously monitors the health of its own power, sensors, memory, and processors using physics-based models of how components fail, and then adjusts its behavior accordingly — for example, thinking less intensively, planning shorter ahead, or reprioritizing tasks as its body ages. This is like a machine developing self-awareness of its own aging, so it can adapt its ambitions to its actual remaining capability instead of running blind until it breaks.

Technical view

The paper proposes Aging-Aware Autonomous Intelligence (AAAI), a framework integrating real-time hardware health estimation directly into an autonomous system's reasoning and planning loop, motivated by the failure mode of 'agnostic collapse' where accumulated, distributed hardware degradation (not a single fault) causes mission failure because the AI stack assumes nominal hardware. The framework rests on three pillars: hardware self-awareness (continuous health estimation of power, sensing, memory, and compute using physics-of-failure models), self-adaptive reasoning (dynamically scaling inference complexity and planning horizon to match remaining capability), and presumably a third execution/mission-adaptation layer. This reframes robustness engineering from static fault-tolerance design toward closed-loop, degradation-conditioned autonomy, giving systems engineers a blueprint for coupling prognostics-and-health-management (PHM) signals directly into planning/task-prioritization logic rather than treating health monitoring as a separate offline concern.

arXiv · cs.ROBuildable

One Future, Every Robot: Label-Efficient Collective-State Prediction with Decentralized JEPA

A robot swarm learns to agree on the future using only whispers between neighbors.

Picture a swarm of robots, each only able to see its immediate surroundings and exchange small messages with nearby robots — can they all independently arrive at the same shared prediction of what the group as a whole will do next? This paper builds CS-JEPA, a system where each robot runs a small predictive model using its recent 16 frames of local observation and tiny 64-number messages passed to neighbors, with no central computer coordinating everything or watching a 'global' view. It's trained first without any labels about the collective outcome (self-supervised learning, similar to how some AI learns patterns just by predicting missing pieces), and only afterward tested using a small number of labeled examples to see how well it captures the group's true future state. Compared to a simpler approach that just tries to directly reconstruct future raw sensor data, this predictive-embedding approach reportedly improves performance in predicting the swarm's collective future using very few labels — useful for coordinating drone swarms or robot teams without expensive centralized control.

Technical view

CS-JEPA is a decentralized recurrent joint-embedding predictive architecture (JEPA) where every robot in a swarm outputs the same shared future 'token field' representing collective state, using only a 16-frame local observation history and one 64-dimensional recurrent message per directed communication edge — no global pooling, target encoder, episode clock, or recorded future actions are required at deployment. Pretraining is self-supervised (no downstream collective-state labels), after which frozen representations are evaluated via ridge regression probes fit on as few as 6–24 globally labeled episodes, testing label efficiency of the learned representation. The comparison baseline is raw-future reconstruction with matched receiver capacity but ~9,607 additional training-only parameters, and a prospectively registered five-seed replication reports improvement for CS-JEPA — a methodologically notable detail since pre-registration guards against post-hoc cherry-picking. This offers a template for scalable multi-robot state estimation under strict bandwidth/compute constraints, and the ridge-probe evaluation protocol is directly reusable for benchmarking other decentralized representation-learning approaches in swarm robotics.

arXiv · cs.ROBuildable

FasTac: A Curved Multispectral Vision-Based Tactile Sensor for High-Speed High-Precision 3D Shape and Force Perception

A curved robot fingertip that sees its own shape and feels forces in real time.

FasTac is an artificial fingertip for robot hands that acts like a tiny eye-and-nerve combo: a camera inside a squishy, curved fingertip watches how light bounces off the skin to figure out its exact 3D shape as it presses on things. It also works out how hard it's pushing and in which direction (straight in, or sideways/sliding), which matters because dexterous tasks like buttoning a shirt or picking up an egg need both shape and force info instantly. The trick is using multiple colors of light from one camera to read the surface, plus a fast onboard chip so results come back almost instantly instead of lagging. This matters because robots that can feel like we do can manipulate objects far more reliably.

Technical view

FasTac combines single-sensor multispectral photometric stereo (multiple simultaneous light-color channels for surface normal estimation) with boundary-prior fast Poisson depth reconstruction for accurate curved 3D reconstruction, and a position-aware dynamic-convolution network (HyperForce) that models the spatially nonuniform stiffness of a curved elastomer to regress three-axis (normal + shear) forces. All processing is accelerated on an FPGA for high-speed inference suitable for closed-loop control. This is a hardware+algorithm co-design that a practitioner could replicate by pairing a multispectral illumination ring with an FPGA pipeline for real-time tactile feedback in grasping controllers.

arXiv · cs.LGBuildable

QQWorld: Quantile-Quantile Matching for World Model Regularization

Fixing a math trick so AI world-models stop ignoring their rarest, weirdest predictions.

AI systems that plan by imagining future states (called 'world models') work best when their internal representation of possibilities follows a nice, predictable bell-curve shape. A previous method tried to nudge these representations toward that ideal shape but its correction signal basically gave up on rare, extreme ('tail') cases, leaving them poorly controlled. QQWorld fixes this by directly matching each data point's rank to where it should sit on an ideal bell curve, so even the oddball extreme cases get properly corrected, and it also cleverly reuses data from previous batches to make this matching more reliable. This matters because better-behaved internal representations mean the AI's imagined futures are more trustworthy, leading to better planning and decision-making.

Technical view

QQWorld replaces the Epps-Pulley (EP) characteristic-function-based regularizer in LeWorldModel with a quantile-quantile (QQ) matching objective that aligns rank-ordered projected latent samples directly against theoretical Gaussian quantiles, avoiding the vanishing-gradient problem EP exhibits for isolated tail samples. A 'cross-batch QQ' variant expands the effective sample pool for ranking using detached samples from prior batches, with an explicit bias-variance analysis of that choice. Practitioners building latent world models for planning can substitute this regularizer as a drop-in loss term to better control heavy-tailed latent distributions, likely improving downstream planning robustness.

arXiv · cs.ROConceptual

TacWAM: Anchor-Guided World Action Model with Mechanics-Aware Tactile Prediction

Teaching robots to imagine future touch — not just future sight — before they act.

Most robots that 'imagine' what happens next only predict what a scene will look like, which misses crucial touch information like how hard something is being squeezed or whether it's slipping. TacWAM teaches a robot to also predict its future sense of touch — forces, bending, and sliding — and uses that imagined tactile future to help decide what action to take next, similar to how you might squeeze a fruit and predict it'll feel softer before you bite. The system carefully combines what the touch sensor sees, measured force patterns, and how the material deforms into one shared internal 'mental picture,' and it uses recent touch history for context, all while making sure this touch-imagining doesn't become a crutch the robot leans on unfairly instead of learning real skills. This matters for delicate tasks like handling fragile or slippery objects where sight alone isn't enough.

Technical view

TacWAM extends World Action Models (that jointly predict future states and generate actions) beyond vision by adding a mechanics-aware tactile future prediction branch. A Spatially Aligned Fusion (SAF) Tactile Encoder maps raw tactile imagery, dense force fields, and deformation flow into a shared latent space, using bilateral force/torque reconstruction as an auxiliary objective to preserve global contact physics; a temporal tactile history encoder supplies context for prediction. The design explicitly guards against tactile futures becoming a 'privileged cue' that the action head shortcuts through rather than genuinely conditioning on, which practitioners can view as a template for adding modality-specific future prediction to action models without inflating an evaluation-time information advantage.

arXiv · cs.ROBuildable

SemAnCorr: Semantic Anchored Correspondence for Zero-Shot Manipulation Skill Transfer

Copy a robot skill from one mug to any mug, even a weirdly shaped one, with no retraining.

Imagine teaching a robot to pour from one specific mug, then wanting it to pour from a different mug that's a totally different shape — SemAnCorr lets it transfer that skill without any new training. It works by finding 'anchor' points on both objects that mean the same functional thing (like 'the handle' or 'the rim'), even if their exact 3D shapes differ, and then spreading that matching consistently across the whole object surface using a mathematical shape-mapping technique. The key insight is that naive point-matching often produces jumbled, inconsistent correspondences, so this method jointly optimizes for both meaning-consistency and overall geometric sense at once. This matters because it could let robots generalize learned manipulation skills across all sorts of everyday object variations without needing separate training for every version of every object.

Technical view

SemAnCorr is a training-free correspondence framework that replaces naive nearest-neighbor descriptor matching (prone to spatially incoherent correspondences) with anchor-guided matching: it jointly optimizes pose and correspondence to select semantically consistent anchor regions, then propagates these as constraints over the full object surface via functional maps, yielding correspondences that are both semantically and geometrically coherent. This recovers reliable local geometric frames needed to transfer object-centric manipulation skills across instances with shared function but differing geometry. A practitioner could adopt this as a preprocessing/correspondence module ahead of any skill-transfer or grasp-retargeting pipeline that currently relies on brittle descriptor nearest-neighbor matching.

arXiv · cs.CVBuildable

Filling the Pareto-Optimal Front for Affordance Segmentation on Embedded Devices Using RGB-D Cameras

Squeezing depth-camera smarts onto tiny wearable-robot chips without sacrificing accuracy.

Wearable robots (like exoskeletons or prosthetics) need to quickly understand what surfaces they can interact with — a curb to step on, a rail to grab — using onboard cameras, but adding depth information (how far away things are) alongside regular color images usually makes the AI models too big and slow for the tiny low-power chips these devices carry. This paper offers two fixes: an automated search process that designs small neural networks specifically built to use depth data efficiently, and a separate technique that takes existing standard networks and retrofits them with a preprocessing step to blend in depth information. Both aim to hit a sweet spot of being accurate, fast, and small enough to run on real portable hardware. This matters because better on-device 'affordance' recognition could make assistive wearable robots safer and more capable in real-world, unpredictable environments.

Technical view

The paper targets affordance segmentation (identifying actionable surface regions) on embedded wearable-robot hardware using RGB-D input, proposing two complementary approaches to explore the Pareto-optimal accuracy/efficiency front: (1) a hardware-aware neural architecture search (NAS) with a newly designed search space that natively incorporates depth channels into compact network architectures, and (2) a fine-tuning approach that adds a preprocessing/fusion layer merging depth with RGB to make depth compatible with conventional (RGB-only-trained) architecture families. Evaluated on real-world datasets against existing tiny-network baselines, the methods aim to overcome failure modes of prior tiny models in critical scenarios under strict embedded hardware constraints. Practitioners deploying affordance perception on portable accelerators (e.g., wearable exoskeleton controllers) could apply either the custom NAS search space or the depth-fusion fine-tuning recipe depending on whether they can afford a full architecture search.

arXiv · cs.RORunnable

When Robots Exchange Meaning: A Demo of Goal-Oriented Semantic Communications for Collaborative Robotics

Robots and edge computers now trade compressed 'meaning' instead of raw video to save bandwidth.

Instead of a robot streaming full video to a nearby computer for processing — which eats bandwidth and adds delay — this demo shows a robot compressing what it sees into a tiny 'meaning code' (imagine describing a scene with a short list of symbolic tokens rather than every pixel), sending that instead, and having the edge computer reconstruct and understand the scene from those codes. The robot uses onboard AI to compress camera images down to a small grid of tokens, sends this compact package to a nearby powerful computer (an Nvidia Jetson), which rebuilds the image, builds a map of the environment, and shows everything on a live dashboard. This matters for future 6G-style robot networks because what really matters isn't how many data packets got through, but whether the robot understood its mission and environment well enough to act — so smarter, meaning-focused compression could let robots work well even over constrained wireless links.

Technical view

This demo implements a task-oriented semantic communications (SemCom) pipeline for a ROS 2 mobile robot (RGB-D + LiDAR) paired with a Jetson Orin edge node: RGB frames are encoded on-robot via an ONNX Runtime VQ-VAE encoder into discrete latent tokens (a 320x240 image becomes an 80x60 token grid, 5400-byte packed payload), transmitted, and reconstructed edge-side via a PyTorch decoder, feeding RTAB-Map SLAM and semantic object handling with browser-based mission visualization. The system operationalizes the 6G task-oriented communication principle that link quality should be measured by mission/task success rather than raw packet delivery. Practitioners building bandwidth-constrained robot-edge systems can use this as a reference architecture for VQ-VAE-based visual token compression integrated with existing SLAM stacks (RTAB-Map) over real wireless links.

arXiv · cs.ROBuildable

UniCross: Unified Cross-Skill Dexterous Manipulation Synthesis

One robot-hand policy that grasps, moves, rotates, and slides objects — no skill-switching needed.

When a robotic hand manipulates an object, it's really doing some combination of four basic moves: grabbing it, moving it around, spinning it in place, or sliding it within the grip — think of adjusting your grip on a pen while writing. Historically, engineers built separate specialized systems for each of these moves, which makes it awkward to smoothly chain them together for complex, real-world tasks the way a human hand naturally does. UniCross instead builds one unified system that treats all four moves as variations of the same underlying problem, sharing the same 'state' and 'action' descriptions and the same overall goal structure. This lets a single trained policy handle all four skills well and combine them fluidly for longer, more complex tasks, much like how a human doesn't consciously switch 'modes' between gripping and adjusting.

Technical view

UniCross unifies grasping, relocation, in-hand rotation, and in-hand translation, previously modeled as separate skills with distinct action constraints/objectives/morphologies, into a single formulation sharing state space, action space, and objective structure. This shared formulation enables distillation of one cross-skill policy that matches or exceeds skill-specific baselines on each individual skill while generalizing to unseen objects/configurations and supporting long-horizon composition without hand-off discontinuities between skill-specific controllers. Practitioners building dexterous manipulation stacks can use this unified state/action/objective design as a template to replace a multi-policy pipeline with a single distilled policy, simplifying long-horizon task composition.

arXiv · cs.ROBuildable

RaDiVe: Robust 4D Radar Odometry with Distance-Bounded NDT and Velocity-Discrepancy Point Uncertainty

Letting cars track their own motion through fog and rain using noisy radar instead of cameras.

Self-driving and robotic vehicles need to know how they're moving even in bad weather, and 4D radar (which also measures speed via the Doppler effect, unlike regular radar) works well in rain or fog where cameras and lidar struggle — but radar data is sparse, noisy, and imprecise, making it hard to match up scans over time to estimate motion. RaDiVe improves this matching process by only comparing nearby points instead of far-apart ones (which reduces errors and speeds up computation) and by trusting each radar point more or less based on how well its measured speed matches the vehicle's expected speed, effectively down-weighting unreliable points. This produces a more accurate, robust way to track a vehicle's position and orientation continuously, which matters for keeping autonomous vehicles safe in weather conditions that blind other sensors.

Technical view

RaDiVe improves 4D radar odometry (registration-based ego-motion estimation from sparse, noisy Doppler-radar point clouds) via two mechanisms: a distance-bounded Normal Distributions Transform (NDT) that restricts correspondence search to near-distance voxel pairs, improving optimization stability and computational efficiency versus full-range NDT matching, and a velocity-discrepancy point uncertainty model that weights each point's contribution by the mismatch between its measured Doppler radial velocity and the radial velocity predicted from the estimated ego-velocity, down-weighting unreliable/noisy points. The method also incorporates signed distance information (truncated in the excerpt) likely for additional geometric consistency. This gives practitioners a concrete recipe — bounded-distance NDT plus Doppler-consistency weighting — for building more robust radar-only odometry pipelines for all-weather autonomous navigation.

arXiv · cs.LGConceptual

ODEWorld: A Continuous Predictive Architecture via Physical-Time Flow

A world model that predicts the future by solving a physics-style equation instead of guessing frame by frame.

Most AI systems that try to predict what happens next in a video or sequence do it in discrete jumps, like flipping through snapshots, even though the real world flows continuously through time. This paper builds a system called ODEWorld that instead learns a smooth, continuous 'flow' describing how things change moment to moment, using the same kind of math (an ordinary differential equation, or ODE) that physicists use to describe motion. Rather than predicting the next snapshot directly, it compresses the scene into a compact internal representation and then mathematically 'integrates forward' through time, much like calculating a rocket's trajectory from its velocity. This matters because it should let AI systems model physical dynamics more efficiently and realistically, which is useful for robots or simulations that need to reason about continuous motion rather than choppy frame-by-frame guesses.

Technical view

PT-Flow parameterizes sequence dynamics as an ODE-defined latent velocity field, recasting future prediction as temporal integration via an ODE solver in a compressed representation space rather than iterative discrete-step decoding. ODEWorld builds on this to create a continuous-time latent world model, extracting time-variant features to structure the latent space for solver stability and efficiency. This approach targets the inefficiency of standard discrete-time video/world-model prediction by exploiting the continuous nature of physical dynamics, and a practitioner could build on it by swapping in different ODE solvers or downstream control/planning heads operating on the learned continuous latent trajectory.

arXiv · cs.ROBuildable

Learning Social Robot Navigation By Sensing Human Legs

A robot learns to dodge pedestrians by watching their legs move, not just treating people as blobs.

Robots that navigate around people usually use a laser scanner mounted low to the ground, which mostly picks up moving legs rather than full bodies, yet most navigation software still just treats each person as a simple circle to avoid. This work builds CALF, a neural network that actually looks at the pattern of leg motion in the laser data and uses that richer information to decide how the robot should move safely and politely around people. It's trained through trial-and-error simulation (reinforcement learning) inside a custom simulator called LegNav that realistically models how legs swing during walking. The point is that understanding gait, not just blob position, should let robots anticipate pedestrians better and behave in more socially appropriate ways.

Technical view

CALF (Convolutional Attention for Leg Features) is an end-to-end policy combining convolutional layers, attention, and an MLP to map raw 2D LiDAR leg-scan patterns directly to navigation commands, trained via deep RL. The authors built LegNav, a lightweight 2D simulator combining LiDAR ray tracing with a novel pedestrian gait model, to generate realistic leg-motion training data absent from prior circle-approximation approaches. Evaluation compares CALF against classical and learning-based baselines on navigation performance and social compliance metrics, suggesting the leg-level representation improves both. Practitioners could reuse LegNav for benchmarking or extend CALF's architecture to other low-mounted-sensor social navigation settings.

arXiv · cs.ROBuildable

Static In, Dynamic Out: Counterfactual Action Augmentation for Moving Object Manipulation

Robots trained only on still objects learn to grab moving ones by imagining where they'll be next.

Robot arms are often trained to pick up objects that stay perfectly still, but in the real world things drift on conveyor belts or sway in the breeze, which breaks those trained behaviors. SIDO tackles this by splitting the problem into two easier pieces: first predict where the moving object will be a moment from now, then figure out how to reach that predicted spot using the same grabbing motion learned from still-object examples. It does this by mentally 'shifting' the training demonstrations to match the predicted future position, effectively imagining a counterfactual version of the demo where the object had been there all along. This is clever because it lets a robot reuse cheap, static training data instead of needing costly demonstrations of every possible object motion, while still handling real-world movement.

Technical view

SIDO factorizes moving-object manipulation into object-pose prediction and pose-conditioned reaching, converting a policy trained only on static demonstrations into a goal-conditioned one via counterfactual action augmentation: demonstrated action chunks are morphed to preserve the hand-object relative pose after displacing the object to a predicted future position. At deployment, an external object pose predictor feeds the future position into this goal-conditioned policy in real time. The method is evaluated across three simulated tasks (Mug, Square, Stack) under five motion patterns plus real-world tests, targeting the common failure mode of static-only visuomotor policies under object drift. Practitioners can apply this as a lightweight augmentation on top of existing action-chunking imitation policies without collecting new dynamic demonstrations.

arXiv · cs.ROBuildable

RoboBRIDGE: A Modular Framework for Bridging Policies to Robust Real-World Robotic Agents

An orchestration layer that turns a raw robot AI model into one that can notice failures and recover.

Vision-Language-Action models let robots turn camera images and instructions into physical actions, but on their own they have no built-in way to notice when something's gone wrong or to keep performing reliably over long, complicated tasks. RoboBRIDGE wraps such a model with a set of coordinated helper modules — one that watches for failures, one that perceives the environment, one that plans next steps, one that controls execution, and one that talks to the actual robot hardware. Think of it like adding a supervisor, a sensor team, a strategist, and a driver around a talented but inexperienced worker (the VLA model) so mistakes get caught and corrected instead of spiraling. This matters because it offers a general, reusable way to make off-the-shelf robot AI models trustworthy in real deployments, rather than requiring costly retraining for every new failure mode.

Technical view

RoboBRIDGE is a modular orchestration framework composed of five coordinated components — Monitor, Perceptor, Planner, Controller, and Robot Interface — layered on top of a pretrained VLA to add failure detection/recovery, long-horizon execution consistency, and robustness to observation/task/embodiment shifts without retraining the underlying model. The Monitor performs rapid failure detection (paired with recovery logic per the abstract) while the other modules handle perception grounding, high-level planning, low-level control, and hardware abstraction respectively. This targets a real deployment gap in current VLA research: policies are strong action predictors but lack systemic robustness scaffolding. Practitioners can plug in different pretrained VLAs or swap individual modules (e.g., a new Monitor) to compose robust agents from existing components rather than building bespoke environment-specific fixes.

arXiv · cs.ROBuildable

DexDirect: Direct Kinesthetic Arm Guidance for Efficient Dexterous Demonstration Collection

You just drag a robot arm by hand and wave your other hand at a webcam to teach it delicate finger tasks.

Teaching robots dexterous hand skills usually requires either expensive motion-capture rigs or awkward, tiring control interfaces, both of which limit how much training data researchers can collect. DexDirect solves this by letting an operator physically grab and drag a robot arm (which cancels out gravity so it feels light) while a single ordinary webcam watches the operator's other hand and translates its movements onto a many-jointed robotic hand. It's like puppeteering the robot directly with your body instead of programming or wearing sensors. In user studies this let people successfully demonstrate tasks far more often than prior camera-only or pose-tracking methods, while also feeling less mentally exhausting, showing that a hybrid physical-plus-visual interface can make collecting robot training data both faster and easier on people.

Technical view

DexDirect combines direct kinesthetic teaching — an operator physically drags a 6-DoF gravity-compensated arm by a handle — with webcam-based hand-pose retargeting onto a 16-joint, 13-DoF dexterous hand, decoupling arm trajectory capture (physical) from hand articulation capture (visual). User studies report 17.2x and 3.2x more successful demonstrations versus AnyTeleop (vision-only) and TeleDex (pose-tracking) baselines respectively, alongside NASA-TLX scores showing reduced mental demand, effort, and frustration at the cost of increased physical demand. Collected demonstrations were used to train a diffusion policy, suggesting the interface is compatible with standard imitation-learning pipelines. This offers practitioners a lower-cost, higher-throughput demonstration collection pipeline for dexterous manipulation without specialized haptic or full-body mocap hardware.

arXiv · cs.ROBuildable

RedFlow: Redirect Failure into Action-Level Corrections for Flow-matching VLA Policy

A robot policy learns from its own mistakes by swapping in what a similar successful attempt would have done instead.

Robot control policies that generate smooth continuous actions (via a technique called flow-matching) tend to drift into errors during real use, and small mistakes compound over time. RedFlow improves such a policy by taking its failed attempts and, instead of throwing them away or only judging whole failed trajectories, pinpointing the exact moment-by-moment actions that caused the failure. It then looks up what a successful attempt did in a similar situation and uses that as a corrective example, essentially saying 'here's specifically what you should have done differently at this step.' This fine-grained, step-level correction is more efficient than coarser methods and helps fix the precise errors that cause failures rather than vaguely discouraging the whole failed attempt.

Technical view

RedFlow is an offline reinforcement learning framework for flow-matching VLA policies that performs action-level (not trajectory-level) credit assignment on failure rollouts via two components: a Context-Aware Corrective Matching mechanism that identifies failure-inducing actions and retrieves successful alternative actions from similar contexts as correction targets, and an Adaptive Redirection Objective that incorporates these corrections into training. This addresses the low sample efficiency of prior offline RL approaches that either discard failure data entirely or apply only coarse trajectory-level penalties, which fail to localize and fix specific compounding errors from distribution shift. Practitioners deploying flow-matching VLA policies could apply RedFlow as a post-deployment fine-tuning stage using logged rollout data, without needing new expert demonstrations for every failure mode.

arXiv · cs.CVBuildable

Articulated Object Reconstruction from Rest-State Observation

AI figures out how a cabinet's hinges and drawers work just by looking at one photo of it closed.

To build realistic interactive 3D models of everyday objects like cabinets or laptops, software normally needs to see the object move — opening and closing — to figure out where the joints are and how they rotate. This paper tackles the much harder case of only having the object in one closed, static position, with no motion to observe directly. It combines several AI tools: one that reads meaning from images (vision-language models), one that separates the object into parts (segmentation), and a video-generating AI that imagines plausible ways the object might move, then checks those imagined motions for geometric consistency to figure out the real joint parameters. This matters because most real-world scans or photos only capture objects in one pose, so being able to infer hidden mechanical structure from a single snapshot would make building digital twins vastly more practical.

Technical view

The method reconstructs articulated objects' geometry and kinematic structure from a single rest-state (closed-configuration) observation, an ill-posed inverse problem since joint motion is never directly observed. It uses an explicit mesh as an intermediate representation to cross-verify and fuse noisy part segmentations from vision-language and segmentation models into spatially consistent parts, then estimates joint parameters by having a video diffusion model synthesize plausible articulation hypotheses, validated via geometric consistency checks against the reconstructed mesh. This targets digital-twin creation pipelines that currently require multi-state motion capture, replacing that requirement with generative motion priors. A practitioner could plug this into existing 3D scanning/reconstruction pipelines to add functional articulation metadata to single-pose object scans.

arXiv · cs.ROBuildable

LabEvolver: Training-Free Experience Evolution for Safe and Grounded Wet-Lab Agents

A lab robot that gets better at chemistry experiments over time just by remembering what worked before, no retraining needed.

Automating wet-lab science with robots is risky because mistakes can be unsafe or costly, and typically AI agents need extensive retraining to improve. LabEvolver instead gives a lab robot a kind of memory: while running a task like preparing a chemical solution, an inner loop handles perception, planning, and safety checks step by step, and afterward an outer loop reviews the completed run and distills useful lessons — skills, strategies, and safety knowledge — into reusable memory, all without updating the underlying AI model's weights. It's similar to how an experienced lab technician gets better through accumulated hands-on experience rather than going back to school each time. The approach cut the time needed for pH adjustment tasks and cut safety-related stoppages substantially, and it also improved performance on a general household-task benchmark, suggesting this learn-by-doing memory trick generalizes beyond just lab work.

Technical view

LabEvolver is a training-free agent framework using episodic memory: a state-grounded inner trial loop handles adaptive perception, online planning, and safety validation during task execution, while an outer evolution loop distills completed trajectories into reusable skill, strategy, and safety experience stored for future retrieval — no model weight updates involved. On robotic pH-regulation solution-preparation tasks it reduced completion time by 48.2% and safety-gate interceptions by 60.0%; on the ALFWorld benchmark it raised cumulative success rate from 76.2% (ReAct baseline) to 91.4% over 500 continual tasks, demonstrating cross-domain generality. This offers a practical, retraining-free path to closed-loop autonomous experimentation, and practitioners could adapt the inner/outer loop memory-distillation architecture to other safety-critical, long-horizon agentic domains beyond wet labs.

arXiv · cs.ROBuildable

Arm2Air: Cross-Embodiment Skeleton Transfer for 3D Relay Formation

Drone rescue networks learn to weave through cities by borrowing moves from robot arms.

After a disaster wrecks cell towers, flying drones can form a relay chain to restore signal — but figuring out where each drone should hover in a cluttered city, avoiding buildings while keeping a strong connected link, is a hard 3D puzzle. Arm2Air's trick is to borrow motion-planning skill from a totally different robot: a robotic arm that's already great at snaking around obstacles in tight spaces. It converts the arm's obstacle-dodging movements into a general 'skeleton' of motion, trains a model on that skeleton, then lightly fine-tunes it for the drone setting using a small amount of real drone data. The result plans drone placements much faster than before, which matters because in an emergency every minute without connectivity counts.

Technical view

Arm2Air pretrains a transformer-based motion-transfer model on ordered obstacle-avoidance skeletons extracted from a pretrained Neural MP model for robot arms, then adapts it to the UAV relay domain with limited target data via Low-Rank Adaptation (LoRA). The transferred skeleton seeds an initial relay-chain layout, refined against connectivity, bottleneck capacity, delay, and movement-cost objectives. On nine held-out high-clutter 3D urban maps, this cut median end-to-end planning runtime by 64.9% versus baseline. Practitioners could replicate the skeleton-extraction-plus-LoRA recipe for other embodiment pairs beyond arm-to-UAV.

arXiv · cs.AIBuildable

World Action Planner: Generalizable Decision-Making with Action-Conditioned World Models

A robot brain that imagines the future before it moves, instead of just reacting.

Most robot AI learns by copying demonstrations, which works great in the exact setup it trained on but falls apart the moment the room, objects, or task changes. World Action Planner pairs a vision-language model (an AI that reasons in words about images) with a 'world model' — a learned simulator that predicts what a scene will look like after an action. The robot proposes a rough plan, then mentally rolls it forward through the world model, checking and refining it through search and optimization before actually acting, like a chess player thinking several moves ahead. This lets it handle new object layouts and unfamiliar task combinations it never explicitly trained on, outperforming policies that skip the 'imagine first' step.

Technical view

World Action Planner combines VLM-based high-level reasoning with a multi-task, pose-image-conditioned world model that generates imagined rollouts of candidate action plans, iteratively refining plans via search and optimization over these rollouts rather than emitting actions directly. It's benchmarked against state-of-the-art VLA and WAM baselines on compositional tasks, novel layouts, and zero-shot generalization, reportedly outperforming both. The replicable idea is decoupling plan proposal (VLM) from plan verification/refinement (world-model rollout + search) — a general test-time-compute strategy for any policy with an available forward dynamics model.

arXiv · cs.ROConceptual

Cross-Embodiment Transfer via Behavior-Aligned Representations

Teaching robots with different bodies to learn from each other's moves, not just their own.

When you train a robot using data from many different robot types — some with grippers, some with suction cups, different arm lengths — combining that data doesn't automatically make any one robot smarter, because each robot's 'vocabulary' of motion differs. This paper asks whether translating actions into a shared, body-independent language — like tracking an object's bounding box, describing motion in plain language, or tracing the gripper tip's path — helps different robots learn from each other's experience. The approach bakes these shared representations into vision-language-action models and tests them on a new simulation benchmark built to measure transfer to unseen robot bodies. The hope is that finding what's common across robots regardless of physical form lets us better exploit growing multi-robot datasets.

Technical view

The authors investigate embedding behavior-aligned, embodiment-invariant representations (object bounding boxes, language-described motions, end-effector traces) into VLA models as intermediate prediction targets to improve cross-embodiment generalization. They build a simulation benchmark specifically designed to isolate and measure transfer quality to novel embodiments, then compare representation choices and integration strategies against standard action-only VLA training. This offers practitioners building multi-robot foundation policies a testable hypothesis (representation invariance predicts transfer) plus a benchmark to validate new representation designs before committing to large-scale training runs.

arXiv · cs.ROBuildable

Failure Detection for Surgical Robot Imitation Policies via Flow-Matching World Modeling

An AI watchdog that senses when a surgical robot is about to mess up.

Autonomous surgical robots are powerful but scary if they fail silently, so you need a way to catch mistakes as they happen — the problem is examples of surgical failures are rare and surgery is highly variable, so you can't just train a detector on 'here's what going wrong looks like.' FoMo-FD sidesteps this by only learning what normal, successful short bursts of surgical motion look like, using a 'world model' that predicts near-future visuals from current video and the robot's planned actions. When live surgery drifts from what the model expects — measured through a statistical mismatch score — it flags a likely failure, without ever having seen a real failure during training. This 'learn only the normal, flag the abnormal' strategy is a practical safety net for robots operating in high-stakes, data-scarce settings.

Technical view

FoMo-FD trains an action-conditioned flow-matching world model to capture nominal short-horizon visual dynamics of surgical manipulation, then detects failures by scoring the 'inverse-transport nonconformity' of observed endpoint latents relative to the model's predicted distribution — a conformal-prediction-style anomaly score over learned dynamics. Detection operates at the window level to flag visual-action inconsistencies, requiring zero failure demonstrations for training, directly addressing the scarce-failure-data problem. Teams building monitors for imitation-learned policies in other safety-critical domains could adopt the same recipe: train a conditional generative dynamics model on nominal data only, then use distributional nonconformity as an anomaly signal.

arXiv · cs.ROConceptual

Corrigible Assistance in One Round: Pragmatic-Pedagogic Best Response

A math proof for how a helper robot can figure out your goal in a single glance.

Imagine a robot that wants to help you but doesn't know your actual goal — it has to watch what you do and guess. Computing the perfect strategy for this guessing game is generally brutal, requiring the robot to plan over every possible future the way a chess engine plans over moves, which is often too slow to be practical. This paper finds a special category of these games where a smarter kind of reasoning — where the human acts more deliberately (pragmatic) and the robot interprets those actions as informative signals (pedagogic) — lets the robot nail down the human's goal in just one step, making the problem solvable quickly rather than requiring exhaustive lookahead. They also show the standard approach (just inferring goals from past behavior) has a hard ceiling on how well it can do, while this pragmatic-pedagogic approach breaks through it by picking actions that only make sense if you're trying to signal your true goal.

Technical view

The paper formalizes a subclass of assistance games (POMDPs with asymmetric goal information) in which pragmatic-pedagogic reasoning — human and robot each modeling the other as approximately rational communicators, à la rational speech act models — collapses the full-horizon POMDP into a tractable single-round best-response computation. They prove standard inverse optimal control has an inherent 'inference ceiling' on goal disambiguation because it treats human actions as pure task execution rather than potential communicative signals, and show the pragmatic-pedagogic policy overcomes this by selecting actions informative precisely because they'd be suboptimal under any goal but the true one. Results are validated experimentally, offering a tractable alternative to full POMDP solving when goal ambiguity is the main bottleneck.

arXiv · cs.ROBuildable

Simulation of Surgical Suturing Using Position-Based Dynamics and the Material Point Method for Robot Reinforcement Learning

A physics sandbox where robots can practice sewing tissue millions of times before touching a patient.

Training a robot to stitch soft tissue with a needle and thread is hard to do safely in the real world, so researchers build simulators instead — but most existing simulators only model the thread or the tissue well, not both interacting realistically together. This paper models the suture thread with position-based dynamics (good for flexible, rope-like objects) and the soft tissue with the material point method (good for squishy, deformable materials), then carefully links the two so the thread and tissue push, pull, and drag against each other believably as a needle passes through. Getting this two-way contact right — friction, tension, drag — is what makes the simulated stitching behave like the real thing. This kind of high-fidelity, safe practice environment is exactly what's needed to train reinforcement-learning surgical robots without risking real tissue or patients.

Technical view

The simulator couples a position-based dynamics (PBD) suture-thread model with a material point method (MPM) soft-tissue model via a novel two-way contact-coupling scheme accounting for frictional and drag forces during needle-thread insertion through deformable tissue, addressing a gap in prior work that typically simulates sutures or soft tissue in isolation. It's positioned as a training ground for robot reinforcement learning on suturing tasks, so practitioners could use it to generate large-scale, physically plausible interaction data for RL policies before real-tissue validation, with the PBD-MPM coupling method itself reusable for other thread-on-deformable-body simulation problems.

SYS

Systems, OS & Low-Level

11 new
arXiv · quant-phBuildable★ flagship

Quantum Fidelity-per-Cost: A Metric for Evaluation of Quantum Computing Systems

A 'fidelity-per-dollar' score to compare cloud quantum computers you actually rent.

You can now rent time on real quantum computers over the cloud, which turns picking one into a genuine buying decision, not just a physics debate. The trouble is every provider charges differently, so it's hard to say which machine gives you the most accurate results for your money. This paper first runs the same test circuits across 14 access options spanning a dozen real quantum chips on four cloud platforms (AWS, IBM, IQM, and OQC) to measure how faithfully each reproduces the intended answer. Then it proposes a single 'Quantum Fidelity-per-Cost' score that combines a measure of result accuracy with what you actually pay, giving a practical, apples-to-apples way to shop. It's an early attempt to make quantum-computer comparison economically honest.

Technical view

The paper delivers a cross-provider measurement study of quantum circuit execution fidelity across 14 cloud QPU access-path entries (12 distinct physical QPUs) over AWS Braket, IBM Quantum Runtime, IQM Resonance, and OQC. It then defines Quantum Fidelity-per-Cost (QFC), which normalizes a fidelity measure — based on KL divergence between measured and ideal output distributions — against each provider's heterogeneous billing model. The contribution is both empirical benchmark data and a cost-aware scoring methodology that makes price-normalized QPU comparison tractable. Practitioners can reuse the QFC metric and benchmark circuits to guide provider/QPU selection under real pricing rather than fidelity alone.

arXiv · cs.DCConceptual

Safe Quotes for Retroactive Liquidity Pools

Making cross-chain crypto trades honest even when some trades might still get canceled.

When you swap tokens on a blockchain trading pool, the price you get depends on how much of each token is sitting in the pool. But if the pool spans multiple blockchains or shards, you can't always guarantee a whole sequence of swaps happens all-at-once — some earlier swap might still be pending, cancelable, or 'locked.' A 'retroactive' pool handles this by tracking every possible outcome (every combination of pending swaps being confirmed or canceled) as a set of parallel virtual pools, and this paper figures out how to quote a new swap so that no matter how the pending ones resolve, the trader is never shortchanged — while still getting close to the best price possible. It's a pricing-integrity problem: promising a fair deal under uncertainty without cheating the trader or leaving money needlessly on the table.

Technical view

Building on Aanes et al.'s retroactive constant-product liquidity pools (which maintain an implicit virtual pool per possible resolution of active cross-chain/cross-shard locks), this paper addresses computing 'safe quotes' — quotes bounded by the minimum possible output across all virtual pool states — as a hard correctness constraint, with a secondary optimization goal of minimizing the gap between the safe quote and the true minimum achievable output. This is essentially a worst-case optimization problem over the combinatorial space of lock resolutions in constant-product AMMs. Teams building cross-chain or sharded AMM infrastructure could use these safe-quote algorithms directly to guarantee price integrity without waiting for full lock resolution, trading computational cost against quote tightness.

arXiv · cs.DCConceptual

A Taxonomy of Performance Metrics for the Distributed Computing Continuum

A cheat-sheet for fairly comparing computers that span the cloud, the edge, and everywhere between.

Modern computing increasingly spreads work across a 'continuum' — powerful data centers, smaller edge servers, and tiny devices out in the field — especially for AI workloads, but there's no agreed way to measure how well such a spread-out system is actually performing. Different researchers currently measure just one slice of the picture, like raw computation speed, network delay, energy use, or final output quality, without connecting these pieces together. This paper instead builds an organized taxonomy — a structured classification scheme — of the performance metrics that matter across these layers, so people can see how compute, networking, energy, and application quality relate to one another. Having this shared map matters because without it, it's hard to fairly compare two systems or know which improvements actually make the overall system better.

Technical view

The paper surveys and systematizes performance evaluation practice for Distributed Computing Continuum Systems (DCCS), which span cloud data centers to resource-constrained edge nodes, organizing metrics into a structured taxonomy spanning computation, networking, energy efficiency, and application-level quality dimensions. It argues existing evaluation work is siloed by dimension and lacks cross-layer consistency, making comparisons between DCCS architectures and algorithms unreliable. The taxonomy is intended as a reference framework researchers can use to select consistent, comprehensive metric sets when benchmarking new continuum architectures, scheduling algorithms, or orchestration systems, rather than relying on ad hoc single-dimension evaluations.

arXiv · cs.NIBuildable

Localization and Pursuit of a Mobile Target using Distance-only Measurements

A robot chases a moving target using only 'how far away is it,' no GPS or angles needed.

Imagine trying to follow someone in a dark field where you can't see them or use a map — all you can sense is roughly how far away they are, based on how weak or strong their radio signal is (this is 'pathloss,' the same idea as your phone losing bars the farther you walk from a WiFi router). This paper builds a system where a stationary receiver and a moving robot work together using only these distance readings, no GPS, no compass, no network of beacons. The method figures out which rough direction the target is in, narrows down its exact spot, then watches how that spot moves over a few readings to guess its speed and direction, so the robot can switch from searching to actually chasing it. They show this takes at most thirteen distance readings to lock onto the target and its motion, and simulations confirm the robot can reliably track it afterward.

Technical view

The system uses only pathloss-derived (noise-free) distance measurements from a stationary origin receiver and a mobile pursuing agent — no GPS, angle-of-arrival, or multi-anchor triangulation. The algorithm first localizes the target's quadrant and position via a bounded search (proven to converge within 13 steps), then differentiates consecutive position estimates to recover a linear motion vector, transitioning the agent from search mode to pursuit mode. Simulations validate bounded tracking error during the pursuit phase. This offers a low-infrastructure alternative to multilateration-based tracking, useful for GPS-denied or anchor-sparse deployments such as indoor or contested-RF environments, and the step-bound result gives a concrete worst-case latency guarantee for practitioners designing real-time pursuit controllers.

arXiv · cs.IRBuildable

A Structured Knowledge Infrastructure for Domain-Specific Data Asset Discovery

Xiaohongshu built a giant knowledge map so its AI stops grabbing the wrong spreadsheet.

At a company with over 5,300 internal data tables, an AI assistant trying to find 'the right table to answer a question' often grabs the wrong one or misunderstands what a metric actually means — like a new employee guessing which spreadsheet to open and misreading the numbers in it. This paper describes a system built at Xiaohongshu (a large Chinese social/e-commerce platform) that pairs a curated knowledge base — documents explaining what each data asset is and how to use it correctly — with a knowledge graph (a map of how thousands of data concepts connect) that quickly narrows down candidates before the AI even starts searching. It also uses a ranking step that recognizes different types of business entities to pick the single best match. The result is a system that finds the right data far more often and uses drastically less computational effort doing it, which matters for any company trying to make AI assistants trustworthy over messy, ever-changing real-world data.

Technical view

The system addresses two failure modes in enterprise RAG over data catalogs: poor retrieval (baseline Hit@10=19.1%) and lack of usage/semantics knowledge causing metric misinterpretation, attributed to four root causes (semantic gap, entity ambiguity, schema drift, asset-usage gap). It combines a three-tier, 179-document knowledge base (structured via an eight-section annotation template, refreshed daily via single-approval hot-reload) with a Graph-Guided Retriever using a 2,859-node knowledge graph as a candidate gate plus intent routing, cutting token usage 71.6x. A Scene-Aware Ranker then applies 19-class entity recognition for final disambiguation. This architecture is a template for large-scale enterprise text-to-data or table-retrieval systems needing both accurate asset discovery and correct downstream metric interpretation at production scale (14 domains, thousands of tables).

arXiv · cs.ARRunnable

LightRot: A Light-Weighted Rotation Scheme and Architecture for Accurate Low-Bit Large Language Model Inference

A custom chip makes AI models run in ultra-compressed 4-bit math without losing accuracy.

To make giant AI language models run faster and use less energy, engineers shrink the numbers inside them down to very few bits (like rounding everything to whole numbers instead of precise decimals) — but this 'quantization' can introduce errors, especially from outlier values that don't compress well. This paper introduces LightRot, a technique that mathematically 'rotates' the model's numbers into a friendlier shape before compressing them, specifically targeting those problematic outliers, paired with custom computer chip hardware built to do this rotation cheaply. Built and tested as real silicon (a 28-nanometer chip), it achieves better energy efficiency than prior designs while running models compressed to just 4 bits. This matters because it pushes toward AI hardware that's both fast and power-efficient enough for wider, cheaper deployment.

Technical view

LightRot combines two algorithmic techniques — Grouped Local Rotation (GLR) and Outlier Direction Aligning (ODA) — with a hierarchical Fast Hadamard Transform (FHT) rotation unit to suppress activation outliers cheaply before 4-bit quantization, addressing the energy overhead that rotation-based quantization methods typically incur. The design was fabricated in 28nm CMOS and measured at 27.4 TOPS/W peak energy efficiency for 4-bit inference, exceeding prior state-of-the-art low-bit accelerators, while the paper claims evaluation beyond basic language modeling benchmarks (unlike some prior rotation-based approaches). Hardware/ML co-design practitioners could adopt the GLR+ODA+FHT pipeline as a quantization-aware rotation scheme, or use the reported efficiency numbers as a benchmark for competing low-bit accelerator designs.

arXiv · cs.ARRunnable

GyRot: Leveraging Hidden Synergy between Rotation and Fine-grained Group Quantization for Low-bit LLM Inference

A chip design finds a hidden trick to compress AI models more without breaking accuracy.

Two popular tricks for shrinking AI models' numbers — rotating the math into a nicer shape, and compressing small local groups of numbers separately — normally clash with each other, because rotation works globally while group compression works locally, like trying to fold a map and shrink individual towns on it at the same time. This paper finds a way to make the two techniques cooperate instead of fight, using a method that coarsely rotates and finely groups the data together, plus a clever reordering trick, so the compression can be more aggressive without losing accuracy. They also redesign the compression math so the whole pipeline can run using only whole-number (integer) arithmetic, which is cheaper for a chip to compute. It's implemented on real integer-based computing hardware, aiming for both more accurate and more efficient extremely-low-bit AI inference.

Technical view

GyRot targets the known incompatibility between rotation-based and fine-grained group quantization for low-bit LLM inference, where rotation's global scope conflicts with group scaling's local scope, typically causing accuracy loss or hardware overhead. Its core contributions are Coarse Rotation, Fine Grouping (CoRFiG) and Harmonic-Aligned Permutation (HAP) to align the two techniques cooperatively, plus a reformulated asymmetric quantization scheme with a zero-point rounding strategy enabling fully integer dequantization (avoiding floating-point overhead). The system is implemented on an INT4-based tensor processing-element architecture via algorithm-hardware co-design. This gives practitioners a concrete recipe — CoRFiG + HAP + integer-only dequant — for combining rotation and group quantization in custom low-bit accelerators without the usual accuracy/hardware tradeoff.

arXiv · cs.CVBuildable

Learning Color Grading, No Photo Sharing: Federated Aesthetic Preference Learning for Personalized Image Enhancement

Your phone learns your personal photo-editing taste without ever sending your photos anywhere.

Apps that auto-enhance your photos to match your taste usually need to see lots of your pictures and ratings on a central server to learn what you like — which is a privacy problem. This paper proposes FedPAIE, a system where your phone learns your personal color-editing preferences locally, using 'federated learning' (a technique where devices train a shared AI model collaboratively without ever uploading raw personal data). It builds a lightweight taste-scoring model, fine-tunes it to you using just a handful of your own photos, then uses that personalized scorer to guide a small on-device color-editing tool — while special safeguards stop the system from 'gaming' its own scorer and producing unnatural-looking edits. The result is phone-friendly, personalized photo enhancement that never has to share your actual photos or ratings with anyone.

Technical view

FedPAIE performs personalized color grading via federated learning, avoiding centralization of raw photos or user ratings. It trains a lightweight dual-cue aesthetic scorer, calibrates it per-user on a small local support set into a personalized scorer, then freezes it as a reward signal to guide regularized adaptation of a lightweight CLUT (color lookup table) enhancer using unpaired local photographs. Fidelity constraints and an excess-gap penalty prevent the enhancer from over-optimizing against the proxy scorer (reward hacking), keeping outputs natural. This gives a practical blueprint for on-device, privacy-preserving personalization pipelines that combine a small learned reward model with regularized preference-guided fine-tuning, applicable beyond photo enhancement to other federated preference-learning tasks on resource-constrained devices.

arXiv · cs.ARConceptual

Analog Courant Numbers and their Role in Analog Computing

There's a hidden speed limit on how fast analog computers can 'think,' just discovered.

Analog computers — which solve equations using physical circuits (resistors, wires) instead of digital 0s and 1s — are being explored again as a fast, energy-efficient alternative to normal chips, especially for representing big grids of numbers (matrices) as networks of electrical connections. This paper discovers that these circuits have a built-in speed limit: no signal can change faster than roughly the bandwidth of the circuit's busiest 'row' (the fastest-responding part), no matter how the rest of the circuit is designed. It's similar to a well-known rule in traditional digital simulations (the Courant condition) that limits how big a time-step a simulation can safely take. The authors worked out the exact formula for this limit and confirmed it holds up in large circuit simulations across different architectures, which matters because it tells engineers designing analog AI or scientific-computing chips exactly how fast their hardware can go before results become physically unreliable.

Technical view

The paper derives a dynamical speed limit for analog computers that represent matrix rows as impedance networks: the fastest normalized eigenmode of the system is bounded by 2π times the largest combined unity-gain bandwidth (CUGBW) across all rows. CUGBW for a row is defined as its finite-gain-adjusted unity-gain bandwidth plus contributions from coupled rows, each contribution being the geometric mean of the two rows' unity-gain bandwidths scaled by their coupling conductance and normalized by the geometric mean of their total conductance loadings. This acts as an analog analogue of the Courant-Friedrichs-Lewy condition in numerical time-stepping, bounding the operator rates physically resolvable by analog hardware, and is validated against large-scale LTspice simulations across multiple architectures. Analog/mixed-signal chip designers can use this closed-form bound to predict, prior to fabrication, the maximum operational speed of impedance-network-based analog solvers (e.g., for optimization or linear-algebra acceleration).

arXiv · cs.NIConceptual

O-RAN: Analysis of Latency-critical Interfaces and Overview of Time Sensitive Networking Solutions

5G networks need near-perfectly timed data delivery, and this paper maps out how to get it.

Modern cell networks (5G and beyond) are moving toward 'virtualized' setups where radio equipment from different vendors runs on shared, general-purpose computer networks instead of dedicated proprietary hardware — cheaper and more flexible, similar to how cloud computing replaced individual company servers. But radio signals need extremely precise, predictable timing to work correctly, and cheap shared networks (like standard Ethernet) aren't naturally built for that kind of split-second reliability. This paper looks at the O-RAN standard (an open, multi-vendor approach to next-gen cell networks) and studies which internal connections are the most timing-sensitive, then surveys 'Time Sensitive Networking' technologies — special techniques that let ordinary networking hardware guarantee tight, predictable delivery timing. It matters because it's a roadmap for making cheap, flexible telecom networks behave with the split-second reliability that used to require expensive dedicated equipment.

Technical view

The paper analyzes O-RAN's disaggregated vRAN architecture, where standardized, multi-vendor interfaces replace traditional tightly-coupled hardware/software stacks, and identifies which fronthaul/midhaul interfaces carry the strictest latency and jitter requirements when running over shared, cost-effective transport (general-purpose Ethernet) rather than dedicated over-provisioned links. It then surveys Time Sensitive Networking (TSN) mechanisms — e.g., traffic shaping, scheduling, and synchronization standards — as candidate solutions for meeting these deterministic performance requirements on shared infrastructure. This serves as a reference for network architects designing O-RAN transport networks, mapping specific TSN standards/features to specific O-RAN interface latency budgets rather than treating TSN adoption as one-size-fits-all.

arXiv · cs.DBConceptual

AgenticER: the next frontier in Entity Resolution

Teaching software to investigate messy duplicate records like a detective, not just pattern-match once.

Entity Resolution is the task of figuring out which records actually refer to the same real-world thing, like matching 'Bob Smith' and 'R. Smith' as one person across different files. Today's tools, even fancy deep-learning and AI ones, mostly make a single snap judgment based on how similar two records look. The problem is real data is messy and scattered across many formats (spreadsheets, JSON, text) and often genuinely ambiguous, so one-shot guessing isn't enough. This paper argues for 'Agentic' entity resolution, where the AI actively gathers more evidence, checks multiple sources, reasons step by step, and even asks a human when it's unsure, much like building a case rather than guessing. This matters because better matching means cleaner data feeding search engines, knowledge graphs, and databases everywhere.

Technical view

The paper contrasts the dominant 'passive paradigm' in ER — static, one-shot similarity computation via rule-based, deep-learning, or LLM methods — with a proposed 'Agentic ER' framing that treats duplicate detection as sequential decision-making. This involves iterative evidence gathering across heterogeneous data-lake sources (CSV, JSON, RDF, free text), multi-hop reasoning, and selective human-in-the-loop intervention rather than a single similarity threshold. It's a position paper motivating a research agenda rather than presenting a system, so practitioners should read it as a framing device for building LLM-agent pipelines (tool-calling, iterative retrieval) around existing ER benchmarks. Difficulty: Conceptual.

SW

Software & Programming

24 new
arXiv · cs.SEBuildable★ flagship

Change2Task: From Repository Changes to Executable Coding Agent Tasks and Environments

Turn a codebase's real pull-request history into ready-made, auto-graded tasks for AI coding agents.

Training and testing AI coding agents needs a steady stream of realistic tasks — each one a real code state, a clear goal, the right tools, and a reliable way to check if the agent succeeded. Hand-building these is slow and eats storage and setup time. Change2Task automates it by mining a repository's merged pull requests (records of real changes developers made) and converting them into fresh tasks on the current, healthy version of that same codebase. It rebuilds the 'broken' starting state through techniques like reversing a patch or mapping old code onto the evolved code, then verifies the whole round-trip works so the task is genuinely solvable and checkable. The result is a scalable supply of verified, executable challenges grounded in real developer work.

Technical view

Change2Task converts merged PRs into verified, executable coding-agent tasks on healthy modern revisions of the same repository, aligning historical evidence with evolved code. It reconstructs task states via three mechanisms — Patch Reversal, Code Mapping, or Agent Reconstruction — and validates the full lifecycle (healthy base → task state → restored state) to ensure solvability and reliable verification. By deriving multiple developer-grounded tasks from maintained environments, it amortizes environment setup, storage, and construction cost across many tasks. Practitioners building agent training/eval harnesses (SWE-bench-style) can use it to continuously generate fresh, verifiable tasks without per-task environment engineering.

arXiv · cs.SEBuildable

PAIChecker: Uncovering and Checking PR-Issue Misalignment in SWE-Bench-Like Benchmarks

A big chunk of the coding tests we use to grade AI is secretly mismatched between the bug report and the fix.

To test whether AI coding assistants can fix real software bugs, researchers build benchmarks by pairing a GitHub issue (the bug description) with the actual code fix (pull request) that resolved it. But this pairing is done automatically and isn't always accurate — sometimes the linked issue doesn't really match what the fix does. This paper checked a well-known benchmark by hand and found that 13.6% of these pairs are actually mismatched in one of eleven specific ways, which means AI models could be graded unfairly. They then built PAIChecker, a system of multiple AI agents working together to automatically catch these mismatches in future benchmarks. This matters because if the tests themselves are flawed, we can't trust the scores AI coding tools get on them.

Technical view

The paper audits SWE-bench Verified, a standard benchmark for LLM issue-resolution, and finds 13.6% of PR-issue pairs are misaligned across five patterns and eleven fine-grained scenarios (e.g., the linked issue doesn't fully describe the problem the patch resolves, or the patch addresses more/less than the issue specifies). PAIChecker is a multi-agent system operating in three phases to automatically detect this misalignment at scale, intended as a quality-control step for constructing SWE-bench-like benchmarks. Practitioners building or curating issue-resolution benchmarks can use PAIChecker to filter or flag unreliable instances before evaluation, improving the validity of reported LLM coding performance.

arXiv · cs.CLRunnable

ORCA-bench: How Ready Are Language Model Agents for Oncall?

Testing whether AI coding agents can actually diagnose a 3am production outage like a human oncall engineer.

When something breaks in a live software system, an 'oncall' engineer has to figure out the root cause by digging through metrics, logs, and traces — often starting from a vague bug report and hours after the problem began, which is a very different skill from writing or fixing code. ORCA-bench is a new test designed to see whether AI coding agents can handle this kind of detective work. It sets up a realistic fake production system, complete with six days of real monitoring data (through tools like Prometheus, Jaeger, and Grafana) and full access to the underlying code, then gives the AI agent over a thousand different incident scenarios that vary in how vague the initial report is and how much time has passed. Human site-reliability experts verified the correct answers, and the AI-based grading was checked against human judgment for consistency, ensuring the benchmark reliably measures real diagnostic skill.

Technical view

ORCA-bench pairs a production-fidelity, OpenTelemetry-instrumented microservice environment (exposing six days of metrics, logs, and traces via Prometheus, Jaeger, and OpenSearch/Grafana, plus full source access) with 1,079 root-cause-analysis tasks that systematically vary report specificity, time-to-detection, and co-occurring fault scenarios. Ground truth is SRE-curated, and the LLM-as-judge scoring is validated against human re-scoring (weighted Cohen's κ=0.90), enabling rigorous comparison across frontier models. This gives agent developers a reproducible, realistic testbed for evaluating and improving RCA-specific capabilities — noisy multi-signal reasoning under time pressure — distinct from standard code-generation benchmarks.

arXiv · cs.AIConceptual

Selective Credibility-Limited Belief Update

A logic for AI reasoning that can accept the believable half of a claim and reject the rest.

In AI knowledge representation, 'belief update' is the formal study of how a rational system should revise its beliefs when it learns the world itself has changed, not just when it gets new facts about a fixed world. Some existing theories let an agent limit which new possibilities it's even willing to consider ('credibility-limited' update), but they treat each incoming piece of information as all-or-nothing — either you accept the whole thing or none of it. This paper's fix is to first transform the incoming information into a 'weaker,' partial version relative to each scenario the agent currently thinks is possible, and only then apply the credibility filter, so the agent can accept the trustworthy part of mixed evidence while discarding the rest. This gives a more realistic model of how rational reasoning systems should handle messy, only-partly-credible information, useful for building smarter automated reasoning or diagnosis tools.

Technical view

The paper extends Katsuno-Mendelzon belief update semantics by inserting, per source world, a transformation of the epistemic input into a weaker proxy prior to applying the credibility-limited transition function, enabling partial incorporation of compound (multi-part) inputs rather than forcing an all-or-nothing acceptance. It provides both semantic (possible-worlds model) and axiomatic (AGM/KM-style postulate) characterizations of the resulting operator class, and identifies well-behaved subclasses with additional properties. This is directly relevant to KR researchers building belief revision/update engines for planning, diagnosis, or multi-agent reasoning systems that need finer-grained control than binary accept/reject update rules.

arXiv · cs.CRConceptual

Formalization of security

Using math-proof software to guarantee security systems are actually secure, not just probably secure.

Proof assistants are computer programs that let researchers write out mathematical proofs so rigorously that the computer itself checks every step for mistakes. Normally, when engineers say a system, program, or encryption scheme is 'secure,' that claim rests on testing and intuition, which can miss subtle flaws. This chapter surveys how proof assistants have been applied to formally verify security guarantees in several areas: whole computer systems, security features built into programming languages, compilers that must not accidentally introduce vulnerabilities, and cryptographic algorithms. Why it matters: this kind of airtight, machine-checked proof is what allows systems to be certified as genuinely secure rather than just well-tested.

Technical view

This is a survey chapter covering the use of interactive theorem provers to formally verify security properties across four domains: system security, language-based security, secure compilation, and cryptography. It frames formal verification as both a design-validation tool and a foundation for certification processes. For a technical reader, it functions as an orientation map to the mechanized-proof literature in security, useful for selecting which proof-assistant techniques and domain (e.g., compiler correctness vs. protocol proofs) fit a given verification goal. Difficulty: Conceptual.

arXiv · cs.CRBuildable

Implementing Homomorphic Encryption-Based Logic Locking in System-on-Chip Designs

Locking a chip's inner privilege controls with encrypted math so the secret key never has to be exposed.

Logic locking is a technique chip designers use to stop their designs from being pirated or tampered with by adding a hidden 'lock' that only works with the correct secret key. The catch with older locking schemes is that the actual secret key values often have to be handed to legitimate users, creating a leak risk. This project instead uses homomorphic encryption, a form of cryptography that lets computations happen directly on encrypted data without ever decrypting it, built on a technique called Ring-LWE. They apply this to protect the sensitive part of a RISC-V processor chip that handles switching between admin and regular user modes, so the lock's secret parameters never need to be revealed. Why it matters: it's a more leak-resistant way to protect valuable hardware designs from theft or reverse engineering.

Technical view

The authors implement a binary Ring-LWE-based logic locking scheme on a RISC-V SoC that secures the privilege-switching logic path without exposing raw locking parameters to end users, unlike conventional logic locking. Measured overhead: the locking module uses 3519 LUTs and 2645 registers, adding 6.0% LUT and 6.9% register overhead versus the unlocked baseline, with an unlock latency of about 2.6 microseconds affecting mainly system-level, not user-level, operations. This gives hardware security practitioners a concrete FPGA-implementable reference design with quantified resource and timing costs for HE-based IP protection. Difficulty: Buildable.

arXiv · cs.SEBuildable

CoGate: Confidence-Gated Co-Decoding for Secure Code Generation

An AI 'security guard' only overrides the code-writing AI when it's actually confident it should.

AI models that write code can accidentally introduce security bugs because they picked up bad habits from their training data. One fix, called co-decoding, pairs the main AI with a smaller 'security expert' AI that nudges each piece of code toward safer choices as it's being written. The problem is existing systems trust that expert's advice blindly, even when the expert is confused by unfamiliar code it's never seen before, which can make things worse instead of better. CoGate fixes this by having the expert's advice only count when the expert itself is confident, otherwise the main AI is left to proceed on its own. Why it matters: safer AI-generated code without sacrificing quality when the safety-checker isn't sure of itself.

Technical view

CoGate modifies the co-decoding acceptance rule to be gated by the security expert model's confidence at each generation step, suppressing the expert's influence when it's operating on unseen or out-of-distribution patterns rather than always applying its steering signal. It's evaluated across multiple LLM backends including CodeGen, DeepSeek-Coder, and Qwen-Coder, positioning confidence-gating as a general improvement to decode-time security steering pipelines. Practitioners building similar expert-guided decoding systems could adopt this confidence-based acceptance rule as a drop-in replacement for uniform acceptance thresholds. Difficulty: Buildable.

arXiv · cs.AIBuildable

LeanCSP: A Framework for Certifying Constraint Reformulation and Solving in Lean

Mathematically proving that a solver's problem-solving shortcuts didn't secretly change the puzzle.

Constraint programming is used to solve hard combinatorial puzzles like scheduling shifts or planning logistics. Before solving, tools often rewrite ('reformulate') the problem to make it easier to crunch, and then a separate solver produces an answer — but errors can sneak in at either the rewriting step or the solving step, and normally we just have to trust both. LeanCSP uses the Lean theorem prover, a tool for writing computer-checked math proofs, to formally verify that reformulations don't change the problem's meaning, and to double-check the solver's answers against outputs from other established solving tools. Why it matters: this creates an end-to-end trustworthy pipeline for automated planning and scheduling systems used in situations where a wrong answer would actually matter.

Technical view

LeanCSP is a Lean-based verification framework operating at two levels: formulation-level, where it proves metatheorems like equivalence, equisatisfiability, and correctness of symmetry-breaking constraints parametrically across entire problem families; and instance-level, where it checks solver-produced certificates via translation backends to external formats (MiniZinc, SMT-LIB, OPB). Combined, these give an end-to-end certified workflow establishing satisfiability/unsatisfiability with formal guarantees rather than trusting solver output directly. Practitioners in verified constraint programming could extend the certificate-checking backends or reuse the metatheorem library to certify new symmetry-breaking techniques. Difficulty: Buildable.

arXiv · cs.SEConceptual

Emerging Challenges in Threat Modeling for GenAI-Augmented Systems: A View from the Trenches

Testing whether old-school hacker checklists still work once an app has generative AI built in.

Threat modeling means systematically spotting security weaknesses in a system's design before it gets built, using structured methods like the well-known 'STRIDE' checklist. The problem is those older methods were designed before generative AI became common, so they may miss AI-specific risks like prompt injection or model manipulation. The researchers reviewed the literature to shortlist newer, AI-aware threat modeling methods, then hands-on applied three of them to a real small business's system that uses generative AI, comparing what each approach caught. Why it matters: it shows that companies bolting AI features onto their products can't just reuse their old security checklists unchanged.

Technical view

This is an exploratory empirical study applying three shortlisted GenAI-aware threat modeling methods to an industrial SME case study of a GenAI-augmented system, benchmarking their threat coverage against each other and implicitly against traditional methods like STRIDE. Results show meaningful divergence in which threats each method surfaces, and reveal systematic gaps in coverage of certain GenAI-specific risk categories. This gives practitioners early empirical evidence on which existing threat modeling methods to combine, and highlights specific risk categories that current tooling underserves. Difficulty: Conceptual.

arXiv · cs.SERunnable

Demystifying Solana Bots: From GitHub Blueprints to On-Chain Fingerprints

Matching public bot code on GitHub to the fingerprints those same bots leave on the blockchain.

Solana is a blockchain platform prized for being fast and cheap, which unfortunately also makes it an attractive target for automated trading 'bots' that exploit price movements for profit — over $250 million a day in bot-related trading volume as of early 2026. Nobody had systematically studied what these bots actually do under the hood or how their strategies show up in the public record of blockchain transactions. The researchers ran a large-scale empirical study, apparently connecting open-source bot code found on GitHub with the actual transaction patterns those bots produce on-chain. Why it matters: understanding these patterns helps exchanges, researchers, and regulators detect and understand automated exploitation happening at scale on fast blockchains.

Technical view

The study performs a large-scale empirical analysis linking publicly available Solana bot implementations (sourced from GitHub) to their observable on-chain execution patterns or 'fingerprints,' extending prior Solana research that focused narrowly on system performance and smart-contract security. It aims to systematize what bot strategies (e.g., arbitrage, sniping, MEV-style extraction) are actually implemented in practice and how they manifest in transaction traces, which is directly useful for building bot-detection heuristics or on-chain forensic tooling. Difficulty: Runnable.

arXiv · cs.CRBuildable

ThreatForest: Multi-Agent Attack Tree Generation with Pluggable TTP Framework Mapping

A team of AI agents that reads your code and auto-drafts an attacker's battle plan against it.

Threat modeling means mapping out how an attacker could break into a system, but doing it manually is slow and requires security expertise that many teams, especially cloud-native ones, don't have on hand. ThreatForest uses a team of AI agents working in sequence: one reads the code repository, another refines the context, others brainstorm possible attack steps and map them onto known catalogs of real-world attacker techniques (like MITRE ATT&CK), then build 'attack trees,' diagrams showing how an attack could unfold step by step, and finally suggest fixes. Throughout the process there are built-in checks and three points where a human reviews the AI's work before it continues. Why it matters: it could make thorough, expert-level security analysis fast and affordable for teams that lack dedicated security staff.

Technical view

ThreatForest implements a multi-agent pipeline — repository analysis, context refinement, threat generation, parallel attack-tree construction with TTP mapping, mitigation synthesis, and report generation — orchestrated as a directed graph with deterministic verification gates, bounded retries, and three human-in-the-loop checkpoints. It supports pluggable adversary technique frameworks (MITRE ATT&CK, CAPEC, cloud-specific threat matrices) and uses a domain-specific sentence-transformer to map generated attack steps onto these TTP taxonomies. Practitioners building reliable multi-agent security tooling over source repositories could adopt its orchestration pattern of verification gates plus staged human review as a reusable template. Difficulty: Buildable.

arXiv · cs.LOBuildable

Certified Sequential Sweep Without Unrolling

A math-based checker proves optimized chip circuits are still equivalent — no brute-force unrolling needed.

Chip designers often 'retime' and rewrite circuit logic to make it faster or smaller, but proving the new version behaves exactly like the old one is notoriously hard for existing tools. This paper builds a verification technique (based on a method called IC3) that first accounts for the retiming, then uses simulation — essentially test-running the circuit — to guess helpful mathematical facts (invariants) that make the proof go through. Unlike older tools that stitch together several different checkers in a fragile, error-prone way, this approach produces an actual certificate: a checkable proof that the equivalence is real. On real circuit benchmarks it beats the best tool from a major hardware verification competition by a wide margin.

Technical view

The authors target sequential equivalence checking (SEC) of circuits after retiming plus arbitrary sequential resynthesis, a class of transformations current EC tools struggle to verify without unsound orchestration of multiple model checkers. Their method preprocesses with retiming, then runs an IC3/PDR-based procedure that uses simulation traces to propose candidate invariants, avoiding unrolling-based BMC/induction pipelines. A key feature is certificate generation — the proof output can be independently checked, addressing the 'trust the checker' problem in EC tooling. Evaluated on retimed/resynthesized open circuit benchmarks, it substantially outperforms the winning portfolio solver from the latest Hardware Model Checking Competition.

arXiv · cs.LOBuildable

Some Experiments with Twee-Style Goal-Directedness

Teaching automated theorem provers to stay focused on the goal instead of wandering into irrelevant proofs.

When a computer tries to prove a math or logic statement automatically, it has to decide, out of thousands of possible next steps, which one to try next — and picking badly wastes enormous time. A tool called Twee got good results by nudging the prover toward facts that share vocabulary ('terms') with the thing it's trying to prove, by rewriting the problem to make relevant connections more obvious. This paper takes that 'stay close to the goal' trick, which had only worked for equations, and extends it to general logical statements, then builds a new, simpler version based directly on shared terms. The early results are described as very promising, suggesting this focus-your-search idea generalizes well beyond its original narrow setting.

Technical view

The paper extends Twee's goal-directed clause selection heuristic — originally limited to unit equational reasoning, where it works by introducing equational definitions to transform the proof problem — to full first-order saturation-based proving. It also proposes an alternative implementation that directly biases clause selection using shared terms with the conjecture, rather than relying on the definition-transformation trick. This addresses a core bottleneck in saturation provers (e.g., Vampire, E, Twee itself): combinatorial explosion of the given-clause loop when heuristics are goal-agnostic. Reported experiments show the shared-term approach yields strong performance gains, suggesting it's a candidate heuristic for integration into general-purpose ATP clause-selection strategies.

arXiv · cs.SERunnable

SWE-NFI: Studying and Benchmarking Coding Agents for Non-Functional Improvements

A new test for AI coding agents: can they make code better without secretly breaking it?

Most benchmarks for AI coding assistants only check whether the code produces the right answer, but real developers spend huge amounts of time making code faster, cleaner, or more maintainable without changing what it actually does — these are called non-functional improvements. This paper builds a benchmark, SWE-NFI, out of 188 real pull requests from open-source Python projects where developers made exactly this kind of quality improvement. It turns each improvement into concrete, checkable rules (92 of them) so an AI agent's changes can be automatically graded not just on 'does it still work' but 'did it actually improve the thing it was supposed to improve.' The goal is to reveal whether today's coding agents, which look impressive on correctness tests, can genuinely refactor and optimize code the way a careful human engineer would.

Technical view

SWE-NFI comprises 188 tasks distilled from merged PRs in open-source Python repos, each paired with behavior-preserving non-functional improvement goals (e.g., performance, readability, maintainability) operationalized into 92 executable rule-based checks. The evaluation suite combines standard functional-correctness testing (to confirm behavior preservation) with rule-based scoring of whether the intended NFI was actually achieved, moving beyond pass/fail correctness metrics used in benchmarks like SWE-bench. State-of-the-art coding agents are evaluated against this suite, quantifying a gap between functional competence and genuine code-quality engineering. The rule/task set and harness appear reusable for benchmarking or fine-tuning agents specifically on refactoring-style objectives.

arXiv · cs.LOConceptual

Extension Types for Free

One elegant type-theory trick quietly unifies several 'partially fixed' type systems used in proof assistants.

In advanced programming-language theory, researchers have invented several different flavors of 'extension types' — types where a value is partly pinned down in advance, like a path between two fixed endpoints, or a term that's locked once some condition holds. These have popped up independently in different systems (cubical type theory, Agda, a tool called cooltt) with their own custom rules bolted on. This paper shows that all of these are really the same idea in disguise, and that you can get them all 'for free' by working inside an existing, well-understood framework called two-level type theory, without inventing any new axioms or building new models. That's valuable because proof-assistant designers don't need bespoke machinery for each variant — the standard theory already contains everything needed, and any existing model of homotopy type theory automatically works for it too.

Technical view

The paper unifies path types (cubical TT, fixed endpoints), Riehl–Shulman extension types (terms fixed on subshapes), and cooltt/Agda's controlled-unfolding mechanism as instances of a single construction inside two-level type theory (2LTT), where the meta-theoretic face/shape calculus governing boundary conditions is already present rather than added axiomatically. The key technical claim is conservativity and freeness: standard models of HoTT automatically become models of 2LTT, so no new semantic construction is required to support extension types across these variants. This gives type-theory implementers a uniform, already-verified foundation for extension-type features instead of ad hoc per-system boundary calculi, and could inform how cubical/extension-type support is added to proof assistants like Agda or forthcoming HoTT-based systems.

arXiv · cs.SEBuildable

From Backlog Items to Security Guidance: Towards Continuous Security Compliance

An AI reads your team's backlog and quietly flags which tickets have hidden security requirements.

In companies with strict security rules (think banking or healthcare software), developers write backlog tickets in short, informal language, and it's easy to miss that a seemingly mundane task actually triggers a security requirement — until an audit catches it later. This paper builds a system that reads each backlog item, uses a classifier to spot whether it's security-relevant, and then — if it is — searches a big pile of official security-requirement documents to pull out the specific guidance that applies, using retrieval-augmented generation (look up the right document, then summarize it). It was built and tested inside a real large enterprise with strict regulatory needs, and the authors also release a dataset of 288 backlog items hand-labeled by nine security experts. The point is to make security compliance a natural, continuous part of everyday sprint planning instead of a scary surprise at audit time.

Technical view

The system pairs a security-relevance classifier (trained/evaluated on a released dataset of 288 enterprise backlog items labeled by nine security experts) with a RAG pipeline that retrieves applicable clauses from security requirements documents to enrich flagged backlog items with actionable guidance. It was developed and validated in situ at a large regulated enterprise, addressing the practical gap between informal agile artifacts (short free-text tickets) and formal compliance documentation. The contribution set includes the labeled dataset, the classifier+RAG architecture, and an evaluation of detection/retrieval quality — providing a reusable blueprint for continuous security-compliance tooling integrated into backlog/ticketing systems (e.g., Jira) rather than periodic manual audits.

arXiv · cs.SERunnable

PROGRESS: Property-Guided Regression Search for Semantic Falsification

Regression tests that actually catch bugs, by letting an LLM write the correct answer instead of copying current behavior.

Automated test generators are great at exploring lots of code paths, but they have an embarrassing flaw: they usually assume whatever the program currently does is correct, so if there's already a bug, the generated test just enshrines that bug as 'expected.' Property-based testing fixes this by checking code against independent rules about what it should do, but writing good rules by hand is hard and doesn't help the tool find its way into deep, hard-to-reach parts of the program. PROGRESS combines both: it has a language model read the code to figure out its intent and automatically write executable correctness rules (properties), then uses those rules to steer a search-based test generator (built on an existing tool called EvoSuite) toward states where the rules might actually be violated. The result is tests that don't just measure 'did we run every line' but 'does the code actually do what it's supposed to.'

Technical view

PROGRESS integrates LLM-generated jqwik properties — derived from intent-bearing code context while limiting implementation leakage — into coverage-guided search-based test generation, extending EvoSuite's DynaMOSA algorithm so the search is fitness-guided toward states that could falsify these semantic properties, not just toward structural coverage. This directly targets the 'oracle problem' in regression testing: purely search-based tools derive expected behavior from the SUT itself, silently codifying existing faults, whereas PROGRESS's LLM-authored properties act as an independent semantic oracle. Practitioners could adopt the pipeline (LLM property synthesis + property-guided evolutionary search) as a drop-in enhancement to existing EvoSuite-based test suites to surface real behavioral bugs, not just increase branch coverage numbers.

arXiv · cs.SEConceptual

TrustChain-Review: A Risk-Adaptive Blockchain and Game-Theoretic Framework for Trustworthy AI-Assisted Code Review

Blockchain plus game theory to keep AI-assisted code reviews honest and accountable.

When AI helps write and review code, it gets harder to know who's responsible if something goes wrong: a developer might submit sloppy AI-generated code, a reviewer might rubber-stamp it, and there's no reliable record of who actually checked what. TrustChain-Review proposes recording verifiable evidence of each review step on a blockchain (so records can't be quietly altered), modeling developers, reviewers, and the platform as players in a game who each have incentives to cut corners or act honestly, and applying stricter oversight rules only when the expected payoff justifies the extra cost. Rather than testing this on real teams, the authors ran a calibrated simulation using a dataset about diff quality, comparing six different governance setups over 30 runs each. It's an early-stage, simulation-based attempt to make AI-assisted code review more accountable rather than a deployed tool.

Technical view

TrustChain-Review couples a blockchain-based evidence ledger for review provenance with a three-player game-theoretic model (developer, reviewer, platform) capturing strategic incentives around verification effort, plus a risk-adaptive rule that escalates governance intensity only when expected benefit exceeds cost. Evaluation is via controlled simulation calibrated against the Diff Quality Estimation dataset, comparing six governance configurations across 30 independent runs — i.e., a mechanism-design/simulation study rather than a deployed empirical evaluation on live repositories. The contribution is primarily architectural/theoretical: a template for combining tamper-evident evidence logging with incentive-compatible governance thresholds for AI-assisted review pipelines, which could inform future implementations on real VCS/CI platforms.

arXiv · cs.SEBuildable

SIGIL: Compiling Agent Skills into Typed Harnesses

AI agents skip half the steps in their own instructions — this compiles those instructions into code that can't be skipped.

Many AI coding agents now follow 'skills' — plain-English procedure documents loaded into their context, telling them steps to follow, like 'run the tests, then check the output format, then verify security.' The problem, this paper finds, is that agents only actually perform 56% of the steps their own skill document requires, even though the final result often still passes surface-level checks — the model is quietly cutting corners while looking successful. Their fix is to 'compile' the prose skill into a harness: real program structure with a typed intermediate format (AG-IR) that clearly separates what the AI model should decide versus what should just be reliably executed as code, so mandated steps can't be silently skipped. This matters because it moves critical, verifiable procedures out of 'the AI promises to do this' territory and into 'the software guarantees this happens,' a much stronger safety property as agents take on more autonomous tasks.

Technical view

The authors measure that across 30 skills and two model generations, prose-driven tool-calling agents execute only 56% of steps mandated by their own skill files, despite passing output-level checks — evidence that skill compliance can't be inferred from output validity alone. Their remedy, Skill Compilation (implemented as SIGIL), converts a prose skill into an executable harness via AG-IR, a typed agentic intermediate representation that explicitly partitions model-owned cognition (things the LLM must still decide) from code-owned control flow (things enforced deterministically), preserving the natural-language authoring surface while eliminating the model's ability to silently skip mandated verification steps. This is directly reusable: teams writing agent skills today could adopt AG-IR-style compilation to convert existing prose skill libraries into harnesses with enforced step execution, trading some flexibility of free-form prose for auditable procedural guarantees.

arXiv · cs.SEConceptual

A Taxonomy of Human-Robot Teamwork Requirements

A field guide to every rule that keeps humans and robots working as one team.

Robots increasingly work alongside people on important, risky jobs — think warehouse cobots or surgical assistants — but the rules for how they should coordinate with humans have been scattered across dozens of manuals, standards, and papers. The researchers gathered 361 such rules from 14 different sources and sorted them into a single organized system: 6 big categories (like keeping humans informed, sharing control, helping with decisions, staying safe, tracking performance) split into 21 more specific subcategories. It's essentially a master checklist that tells engineers everything a robot needs to do to be a good teammate. This matters because without a shared framework, different companies and industries end up reinventing (or missing) critical safety and collaboration rules.

Technical view

The authors performed a systematic literature and standards review across academic and industrial sources to build a 361-requirement corpus for Human-Robot Teamwork (HRT), then applied iterative qualitative coding to derive a two-level taxonomy with 6 top-level categories (information provision, relational control, decision support, safety mechanisms, performance monitoring, and a foundational category) and 21 subcategories. This provides a reusable reference model that requirements engineers can map existing systems against, use to identify coverage gaps in a given domain's standards, or extend as a checklist during HRT system specification and certification. It's a synthesis/classification contribution rather than a new algorithm or system.

arXiv · cs.LOBuildable

From Lecture Notes to Lean: Formalizing a Textbook on Probability Theory

Turning a whole probability theory textbook into code a computer can verify line by line.

As AI gets better at generating math proofs, we're heading toward a flood of proofs that look right but might not be — so having a way to have a computer double-check them becomes crucial. This project takes a full 14-chapter college textbook on probability theory (covering advanced topics used in statistics and finance) and translates every definition and proof into Lean, a programming language that mathematicians use to have a computer verify logical correctness. The 'how' is painstaking manual translation of math notation into precise code that a proof-checking program can step through and confirm. The payoff is a trustworthy, machine-checked version of the textbook plus a library of reusable building blocks that future projects can build on instead of starting from scratch.

Technical view

This is an ongoing formalization effort in the Lean theorem prover encoding the full content of an upper-level probability theory textbook, spanning Riemann–Stieltjes integration through martingales and limit theorems, likely built atop Lean's Mathlib measure theory library. The contribution is both a machine-checked artifact (verified statements and proofs matching the textbook) and reusable Lean infrastructure (lemmas, definitions, typeclasses) for future probability-related formalizations. Practitioners can build on this by importing the library for their own formalization projects or using it as a template for large-scale textbook formalization workflows.

arXiv · cs.SERunnable

AgentS4D: Benchmarking Runtime Risks across the Execution Lifecycle of LLM-Based Workspace Agents

A stress-test lab exposing exactly how AI office assistants can quietly go rogue mid-task.

AI agents that manage your files, calendar, or workspace don't just answer one question — they take multi-step actions over time, which means something can go wrong at any point along the way, not just at the final answer. This paper builds a sandbox testing environment with 328 deliberately risky scenarios to see where things break down: where does a bad instruction sneak in, how does it trick the agent into unsafe behavior, what kind of harm results, and at what point in the process can you catch evidence of the problem? Think of it like a safety obstacle course with checkpoints, rather than just checking the finish line. This matters because catching risks only after the fact is too late — you want to know which stage of a long AI workflow needs better guardrails.

Technical view

AgentS4D is a sandboxed benchmark for lifecycle-wide runtime safety evaluation of LLM-based workspace agents, organized around a four-dimensional framework: six risk-entry sources, six induction strategies (how unsafe behavior gets elicited), nine target harm categories, and seven lifecycle checkpoints for post-run evidence collection. It contains 328 risk-injected cases spanning stateful, multi-step, tool-using workflows, enabling evaluation of not just final-outcome safety but where in an execution trajectory risk originates and manifests. Practitioners building or auditing agent systems could use this to pinpoint which stage of their pipeline (tool call, state mutation, side effect) needs stronger monitoring or intervention rather than relying on end-of-trajectory checks alone.

arXiv · cs.AIConceptual

PIE-APT: A Unified Framework for Temporal Planning and Contradiction Hunting via Incremental Direct-Derivation Abduction

Teaching AI to plan through time while hunting down contradictions in what it thinks it knows.

Imagine trying to plan a sequence of actions in a world where your knowledge is incomplete and things change over time — like a detective updating their theory as new clues appear, but for an AI reasoning system. Existing methods for this either get stuck in impossible-to-solve logic puzzles or require searching through an overwhelming number of possibilities. This paper introduces two connected tools: one that fills in logical gaps efficiently (rather than brute-force searching), and one that plans actions across a timeline using those filled-in gaps, both built on a rigorous logical framework (Description Logic) that guarantees the reasoning stays solvable rather than spiraling into an unanswerable problem. This matters for systems like knowledge graphs used in search engines or AI assistants that need to reason about how the world changes over time without breaking down.

Technical view

The paper presents PIE-Abducer (incremental direct-derivation abduction) and PIE-APT (Abductive Planning for Temporal Knowledge Graphs), operating natively in Description Logic to avoid the decidability issues and Ramification Problem that plague standard action formalisms. State transitions are modeled as non-monotonic updates to deductively closed DL theories along a linear timeline, treating the incremental reasoner as a black box and representing actions directly in OWL without external modal operators — preserving logical decidability while avoiding the combinatorial blowup of structural abduction for incomplete knowledge. This gives knowledge-graph practitioners a decidable, OWL-native mechanism for temporal planning and inconsistency/contradiction detection over dynamic knowledge graphs, useful for building reasoners that must handle open-world, evolving data.

arXiv · cs.LGConceptual

Benchmarking the Residual: What Long-Horizon Evaluations Add Beyond Matched Short-Task Performance

Why AI agents flop on long tasks: is it harder steps, or does the mess just pile up?

When AI agents fail more on longer tasks, it's tempting to assume 'longer = harder,' but this paper points out there are actually different possible culprits: maybe longer tasks just have more steps where small mistakes can snowball, maybe the individual decisions get genuinely tougher, or maybe the agent's own growing pile of past conversation and tool outputs (sometimes called 'context rot') actively makes later steps harder even if they weren't hard to begin with. The authors propose a fix for benchmark design: don't just measure how well an agent does on a long task, compare it to a prediction of how well it *should* do based on stitching together its performance on the same task's short individual pieces. The gap between that prediction and reality — they call it the 'horizon residual' — tells you whether something about the long task itself is uniquely damaging, rather than just being a sum of hard steps. This matters because it separates 'agents need to get smarter' from 'agents need to stop poisoning their own context,' which call for very different fixes.

Technical view

This position paper argues that claims of 'long-horizon failure' are underspecified unless benchmarks compare actual full-task success against a baseline prediction constructed from matched short, individual-stage performance — since compounding of ordinary per-stage errors alone can explain degradation without invoking any horizon-specific effect like context rot. They formalize this comparison as the log-ratio between the short-task-derived prediction and actual long-task success, termed the 'horizon residual,' which isolates trajectory-induced degradation (where earlier execution genuinely makes later work harder, e.g., via accumulating context) from mere multiplicative compounding of independent per-step error rates. Benchmark designers could adopt this residual metric to diagnose whether their long-horizon evaluation is actually measuring something new versus just restating known short-task failure rates.

DEV

Semiconductors & Devices

16 new
arXiv · quant-phConceptual★ flagship

On Optimal Measurement-State Preparation via Geometric Transport of the Squeezing Ellipse

Steering a quantum 'squeezed' light state along a clever path to sharpen precision measurements.

Squeezed states are special quantum states that let you measure things more precisely than normal by trading uncertainty from one property into another — imagine squeezing a round balloon into a narrow ellipse so it's very thin in the direction you care about. But to get the full benefit, that ellipse has to point the right way, and often it starts misaligned. This paper describes a geometric method to guide a misaligned squeezed state into the optimal orientation by moving its average state along a controlled path on a sphere, letting the ellipse rotate on its own as a bonus 'free' degree of freedom. Strikingly, how much the ellipse turns depends only on the area enclosed by the path — a beautiful link to the famous 'geometric phase' in physics. The approach is platform-independent, illustrated here with polarization-squeezed light.

Technical view

The work presents a geometric-transport framework for preparing measurement-optimal squeezed states in SU(2)-symmetric systems, treating the squeezing-ellipse orientation as an extra geometric degree of freedom that evolves as the mean state traces a controlled trajectory on the Bloch/unit sphere. For the relevant transformation class, the induced ellipse rotation is fixed by the solid angle enclosed by the path, establishing an explicit connection to the geometric (Berry) phase. This yields a path-design principle: choose trajectories whose enclosed solid angle rotates a misaligned squeezed input into the metrologically optimal orientation. The authors outline a concrete implementation with polarization-squeezed light using continuously varying birefringent elements, making it adaptable across metrology platforms.

arXiv · cond-mat.str-elConceptual

Lattice composite Fermi liquid with broken inversion symmetry

Breaking a crystal's mirror symmetry makes exotic 'half-particle' currents behave in strange, measurable new ways.

Composite fermions are quasiparticle stand-ins that emerge when electrons bind to magnetic flux in certain quantum materials, and they underlie exotic states like the fractional quantum Hall effect. This paper studies composite fermions living on a crystal lattice in a special electronic band structure (a half-filled Chern band) that lacks inversion symmetry, meaning the material looks different from its mirror image. The authors show that this broken symmetry lets internal fluctuating fields produce oddly 'kinked' (non-smooth) patterns in the material's electrical resistance as a function of frequency, plus a one-way, direction-dependent conduction effect. These signatures could be tested experimentally by bouncing sound waves across the material's surface. It matters because it opens new experimental fingerprints for probing this hard-to-detect exotic electronic state.

Technical view

Analyzes transport in lattice composite Fermi liquids (CFLs) formed at half-filling of inversion-broken Chern bands, extending beyond the standard HLR (Halperin-Lee-Read) Landau-level treatment. Predicts a non-analytic AC longitudinal resistivity Re ρxx(ω) ~ |ω|^(4/3) from gauge-field fluctuations under gate-screened Coulomb interaction, plus nonreciprocal transport and a Hall conductivity scaling ~|q| at finite wavevector, both experimentally accessible via surface acoustic wave (SAW) measurements. Also identifies a separate singular-transport mechanism from renormalization of 2k_F backscattering. Offers concrete, falsifiable SAW-probe predictions for inversion-broken Chern-band CFL candidate materials.

arXiv · cond-mat.stat-mechConceptual

Quantum Chaos and Diffusive Transport from Geometric Randomness

Random graph shapes alone — no particles interacting — can make quantum systems behave chaotically.

Normally physicists think you need many interacting particles or messy disorder to get 'quantum chaos,' the unpredictable, jumbled energy patterns seen in complex systems. This paper shows you can get the same chaotic behavior using just non-interacting particles moving on randomly connected graphs (networks of nodes and links) that are shaped like layered trees, even with perfectly uniform connection strengths — the randomness is purely in the geometry, not the physics. They find that if each layer of the graph is large ('extensive'), you get robust chaos and diffusion (particles spreading out like ink in water), but if the graph is narrow and thread-like, the system instead traps particles in localized pockets. This matters because it separates the geometric ingredient from other known causes of chaos, suggesting shape alone can be the whole story.

Technical view

The authors study non-interacting quantum particles on random locally tree-like layered graphs (structurally disordered generalizations of square lattices/ladders, equivalently random 1D chains of coupled components) with uniform coupling strengths, so all randomness is purely geometric rather than in the Hamiltonian's matrix elements. They show that extensive layer size produces level repulsion (a hallmark of Wigner-Dyson statistics), robust quantum chaos, and diffusive transport, while the quasi-1D limit yields coexisting localized states instead. This establishes graph dimensionality/geometry as an independent chaos-inducing mechanism, offering a tunable toy model for probing the boundary between many-body-localization-like and ergodic regimes without needing interactions or on-site disorder.

arXiv · cond-mat.mes-hallConceptual

Anomalous metal and superconducting phases in rhombohedral graphene

Graphene stacked just right sometimes 'forgets' how to fully become a superconductor.

Superconductivity is when a material carries electricity with zero resistance, and scientists have found it in graphene (sheets of carbon one atom thick) stacked and tuned with electric fields. Here researchers studied a special stacking called rhombohedral graphene sitting on another material (WSe2) that boosts unusual electronic effects. Depending on exactly how they tune the material's voltage, some regions become true zero-resistance superconductors, while nearby regions look almost identical but stubbornly keep a small amount of resistance instead of dropping to zero. They also found that applying a magnetic field sideways to the sheet can push these weird 'stuck' regions to merge with the fully superconducting ones. This matters because it's a clue about mysterious 'anomalous metal' states that seem to sit between normal conduction and true superconductivity, something physicists still don't fully understand.

Technical view

The authors map gate-voltage phase space in WSe2-proximitized rhombohedral graphene, distinguishing pockets with true zero-resistance superconductivity from adjacent pockets exhibiting finite saturation resistance despite otherwise matching phenomenology (sharp transitions vs. temperature, perpendicular field, and current). This directly probes the 'anomalous metal' phase debate in 2D superconductors, where quantum phase fluctuations or vortex dynamics are hypothesized to prevent full resistance collapse. The key experimental lever is in-plane magnetic field, which expands and merges the zero-resistance regions with the finite-resistance ones, implicating spin-orbit or Zeeman-related physics tied to WSe2 proximity coupling. This gives a tunable platform for testing theories of dissipative superconducting-like states and unconventional pairing mechanisms in moiré-free rhombohedral graphene.

arXiv · physics.comp-phRunnable

Fast and Accurate Foundation Models for Equivariant Machine-Learned Interatomic Potentials

New AI models predict how atoms move almost as fast as cheap approximations but nearly as accurate as expensive physics.

Simulating how atoms and molecules move over time (molecular dynamics) is essential for designing new drugs, batteries, and materials, but doing it accurately with real physics equations is painfully slow. Machine learning has stepped in with 'interatomic potentials' — AI models trained to predict atomic forces quickly — and some newer ones bake in the actual symmetries of physics (like rotation and reflection rules) to be more accurate, though historically that made them slower. This paper shows how to get the best of both: models trained on enormous datasets that keep the physics-respecting accuracy while running about as fast as the quicker, less rigorous alternatives. This matters because faster, accurate simulations mean scientists can explore far more chemical possibilities before ever stepping into a lab.

Technical view

The paper investigates the speed-accuracy trade-off in equivariant machine-learned interatomic potentials (MLIPs), which encode physical symmetries (rotational/reflection equivariance) directly into network architecture, historically at a computational cost disadvantage versus invariant models at scale. Using the NequIP and Allegro architectures trained on very large, diverse datasets — a regime where data efficiency matters less than raw capacity — they present a family of foundation MLIPs that reportedly match leading inference and training speeds while retaining equivariant accuracy. Practitioners doing MD-based materials/chemistry screening could fine-tune these foundation models on targeted chemical spaces, gaining both the sample efficiency benefits of equivariance and throughput competitive with faster invariant models.

arXiv · cond-mat.mtrl-sciRunnable

Transport Evidence of Magnetic Polarization in the Altermagnetic Candidate MnTe

A magnet-that-shouldn't-be-magnetic material shows surprising magnetic behavior once grown as a thin film.

Altermagnets are a recently identified class of materials that are technically 'compensated' — meaning their internal magnetic fields should cancel out to zero overall — yet they can still behave in magnet-like ways useful for next-generation computer memory and spin-based electronics. Here, researchers grew ultra-thin films of the altermagnet candidate MnTe on a specific substrate and measured how electrical current flows through it under a magnetic field, finding a distinctive 'butterfly'-shaped pattern that suggests the material actually has some net magnetization, contrary to the simple picture. Using computer simulations, they show this could come from the film's surface disrupting the material's usual symmetry, or from tiny atomic defects. This matters because controlling and understanding this hidden magnetism is a step toward using altermagnets in real spintronic devices.

Technical view

The authors grew epitaxial α-MnTe thin films via molecular beam epitaxy on InP(111) substrates and performed low-temperature magneto-transport measurements, observing a hysteretic butterfly-shaped longitudinal magnetoresistance and nonlinear transverse magnetoresistance — signatures inconsistent with MnTe's nominal compensated antiferromagnetic ground state and indicative of finite net magnetization. DFT calculations identify plausible mechanisms including interface-induced symmetry breaking and point-defect-mediated magnetization. This is experimental evidence relevant to altermagnetic spintronics, where researchers exploiting MnTe's predicted spin-split bands (despite zero net moment in bulk) would need to account for thin-film-induced magnetization as both a complication and a potential tunable control knob for device engineering.

arXiv · eess.SYConceptual

Anonymous sharing is pairwise phase-blind

Math shows shared storage doesn't actually cause AI training jobs to sync up and jam.

When many independent AI training jobs share the same storage system, they periodically all try to save their progress (a 'checkpoint') at once, creating a huge traffic jam — this is called a 'checkpoint storm,' and it's widely assumed to be self-reinforcing, like people falling into step on a bridge. This paper borrows the math used to describe synchronizing fireflies or heartbeats (oscillators nudging each other into rhythm) and applies it to computer jobs sharing a resource. It finds that if the shared resource treats all active users the same way, regardless of who they are, two jobs writing to it don't actually push each other in or out of sync at all — the mutual nudging effect that causes storms in the classic math models is completely absent, not just weak. This matters because it undercuts the standard explanation for a costly, real infrastructure problem and suggests engineers should look elsewhere for the real cause.

Technical view

The paper models checkpoint-writing training jobs as integrate-and-fire oscillators coupled through a shared bandwidth-limited resource, the same framework underlying Kuramoto and Mirollo-Strogatz synchronization theory. It defines 'anonymous' resources as those whose delivered rate depends only on the count of active users, not their identity, and proves that for identical jobs with write time shorter than compute interval, the two-job phase-gap return map is exactly the identity — under storage contention, a shared power cap, or both. This means the pairwise coupling term the classical phase-locking frameworks require is not merely small but zero, so checkpoint storms cannot be explained by two-body phase-locking dynamics in anonymous systems. Practitioners investigating checkpoint storms should look to higher-order (N-body) effects, non-anonymous resource policies, or job heterogeneity rather than pairwise synchronization as the driving mechanism.

arXiv · eess.SYBuildable

A Sub-6G Mixer First RXFE with LO Overlap Reduction and 1.08 dB NF Degradation

A cleverer radio chip trick shaves noise off phone signal reception below 6 GHz.

Inside every phone or wireless device is a receiver chip that has to pick a faint signal out of noisy airwaves, and one common design (called 'mixer-first') has a flaw: a timing overlap in its internal switching clock quietly degrades how cleanly it can lock onto a signal and how much extra noise it adds. This paper designs a fix for that overlap problem and builds an actual chip in a standard 65-nanometer manufacturing process to prove it works. The 'how' involves a specific clock-generating circuit (current-mode logic) tuned to minimize that overlap. The result is a receiver that adds very little extra noise (just 1.08 dB) while working across a wide range of frequencies used by phones and other wireless devices — meaning better reception with less power and chip space.

Technical view

The work identifies and mitigates local-oscillator (LO) pulse overlap in a mixer-first receiver front-end (RXFE), a known but under-addressed cause of input-matching (S11) and noise-figure (NF) degradation, using a CML-based LO generator design methodology to suppress overlap. Fabricated in TSMC 65nm CMOS, the chip achieves S11 below -10 dB, NF degradation of only 1.08 dB, and 12.19 mA current draw from a 1.2V supply across 1–5.6 GHz, in a compact 302×209 μm active area. RF/analog IC designers working on sub-6GHz mixer-first receivers (common in software-defined radio and cellular front-ends) can adopt this LO-generator methodology directly to improve NF and matching without changing the core mixer topology.

arXiv · physics.app-phRunnable

Matching Trace Element Distribution to Mineralogical Phases in Ancient Biotechnology-Derived Metallic Salts: a Multimodal Analysis

X-ray detective work reveals exactly where trace metals hide inside a 2,400-year-old cosmetic.

Ancient Greeks used a lead-based white powder called psimythion as both makeup and medicine, and scientists want to know exactly how it was made and what impurities it contains — but two standard analysis tools (one that identifies which chemical elements are present, another that identifies which crystal structures/minerals are present) normally give separate, averaged-out answers that can't be matched to each other spatially. This paper combines those two X-ray techniques with a third, higher-resolution X-ray imaging method on the same physical spot of sample, including a version the researchers made themselves using a documented ancient recipe, so they can literally see which trace elements sit within which mineral crystals. This matters for archaeology and history of medicine because it can confirm authentic production methods, contamination, or degradation over 2,400+ years in a way bulk chemical averages never could.

Technical view

The study combines spatially resolved X-ray fluorescence (XRF), X-ray diffraction (XRD), and nanoscale X-ray imaging on the same sample regions of archaeological and lab-synthesized lead carbonate (psimythion, PbCO3) to co-register trace-element distributions with specific mineralogical phases — something bulk XRF/XRD alone cannot do since each yields separate averaged datasets. The experimental reference sample was synthesized per a documented 4th century BCE recipe, giving a ground-truth comparison for the archaeological material. This multimodal, spatially-correlated methodology is directly applicable to other cultural heritage or forensic materials science problems where elemental and structural data need to be tied to the same microstructural location rather than treated as independent bulk measurements.

arXiv · eess.SYBuildable

A subspace approach to data-driven predictive control for linear parameter-varying systems

Controlling a machine whose behavior keeps changing, using only its past data — no model required.

Many real systems — like a robot arm carrying different loads, or a vehicle whose dynamics change with speed — don't behave the same way all the time; their behavior depends on some changing condition, called a 'scheduling' variable. Traditionally, controlling such a system means first building a precise mathematical model of exactly how it behaves under every condition, which is hard and error-prone. This paper instead shows how to control the system directly from recorded input/output data, skipping the model-building step entirely, by mathematically separating out the effects of past behavior, planned future inputs, and the changing conditions, then using linear algebra tricks to keep the amount of computation needed manageable even with large datasets. This matters for engineers building controllers for machines with time-varying or condition-dependent behavior, since it saves the difficult modeling step while still making reliable predictions.

Technical view

The paper develops a subspace-based data-driven predictive control (DDPC) method for linear parameter-varying (LPV) systems, deriving a multi-step predictor from an affine LPV state-space innovation form that separates contributions of past data, future inputs, scheduling trajectories, and innovations, then projects onto the row span of lifted input-output-scheduling data to get an asymptotically unbiased predictor usable directly in receding-horizon control without explicit LPV system identification. To keep the online optimization tractable, they extend γ-DDPC to the LPV setting via LQ factorization, fixing the number of online decision variables independent of dataset length, plus a reduced-order predictor to curb the otherwise exponential growth in scheduling-related terms. Control engineers working with gain-scheduled or parameter-varying plants (e.g., robotics, aerospace, process control) could apply this to implement MPC-style controllers straight from data logs, bypassing costly LPV model identification while retaining tractable online computation.

arXiv · cond-mat.mes-hallConceptual

Observation of long-lived spin order in nanoconfined water

Water squeezed into nanoscale channels can hold onto strange magnetic memory for surprisingly long stretches.

Water trapped inside incredibly tiny tunnels (5.6 nanometers wide — thousands of times thinner than a hair) behaves very differently than water in a glass. Researchers used a super-sensitive magnetic sensor built from a defect in diamond, called a nitrogen-vacancy center, to listen to the faint magnetic signals from hydrogen atoms in this squeezed water. Because the water barely moves in such tight quarters, its magnetic signal stays clear enough to detect, and occasionally it splits into two distinct signals — a sign that something unusual, possibly charged particles knocked loose by laser light, is briefly locking the water's magnetic state in place. This matters because it hints at hidden, short-lived chemical states that could reshape how we understand water and chemistry in confined spaces like rock pores, cells, or nanotech devices.

Technical view

Using NV-center magnetometry to perform NMR spectroscopy on water confined in 5.6 nm channels, the authors observe strongly suppressed diffusivity that permits direct 1H spectral detection despite the reduced sample volume. Intermittently the proton line splits into a doublet with tens-of-kHz splitting, attributed to hyperfine coupling to long-lived paramagnetic charge complexes seeded by laser-injected solvated electrons. The metastable, intermittent nature of the feature suggests a transient photochemical species rather than a steady-state impurity effect. This establishes NV-NMR as a viable probe of nanoconfined liquid dynamics and opens a route to studying photoinduced radical chemistry at the nanoscale in situ.

arXiv · physics.ins-detConceptual

Design and beam-test characterization of the CRILIN semi-homogeneous crystal calorimeter

A new crystal detector times particle collisions to within 50 trillionths of a second.

This is about building better detectors for the giant particle-smashing experiments planned for future colliders that crash electrons together. The team built a large test detector out of stacked lead-fluoride crystal blocks paired with light sensors, designed to catch and measure the energy and timing of particles as they crash into it. They tested it by firing real electron and muon beams at CERN and measuring how precisely it could time and locate each hit. The payoff is a detector design that's fast, finely detailed, and tough enough to survive years of radiation, helping physicists pin down particle properties with much greater precision at the next generation of collider experiments.

Technical view

CRILIN is a longitudinally segmented, semi-homogeneous PbF2 Cherenkov calorimeter (~22 X0 deep) read out by UV-extended SiPMs, targeting fast timing and fine transverse/longitudinal granularity for future lepton colliders. A five-module (7×7 crystal matrix) prototype was beam-tested at the CERN SPS with 10–120 GeV electrons and 150 GeV muons. The system achieves sub-50 ps time resolution for electrons above 10 GeV, improving further at higher energy, validating the single-channel 4-SiPM-per-crystal readout scheme. This demonstrates a scalable design path for combining Cherenkov-based fast timing with shower-shape reconstruction in a radiation-tolerant EM calorimeter.

arXiv · eess.SYBuildable

On the Implementation of Two-Parameter Stabilizing Controllers Using Stable-Block Input-Output Feedback Structures

A new recipe lets engineers build tricky feedback controllers using only 'safe' building blocks.

In control engineering, you often need a controller — the math and logic that keeps a system like a drone or chemical plant stable — with two independent tuning knobs, one for tracking commands and one for rejecting disturbances. For some tricky systems, the straightforward way to build such a controller requires an internally unstable piece, which is risky because it can behave unpredictably in real hardware. This paper shows a general method to reorganize any such controller so it's built entirely from stable, well-behaved pieces wired together in a loop, without sacrificing how well it performs. This matters because it makes advanced control designs safer and easier to actually implement in real machines, with extra practical perks like better handling of actuator limits.

Technical view

The paper presents a universal 2-DOF (two-degree-of-freedom) stabilizing controller implementation using only stable constituent blocks, applicable to any regular SISO/MIMO plant, including those violating the parity interlacing property that normally forces an unstable controller realization. By applying Youla-Kučera parametrization within an input-output feedback topology, controller synthesis is decoupled from its physical realization, so performance specs can be chosen freely and then mapped onto a cyclic arrangement of stable blocks. This yields practical benefits like localized anti-windup and simplified initialization compared to existing algebraic factorization approaches that trade off design freedom for block stability. Control engineers can use this as a drop-in realization scheme for otherwise-unstabilizable controller designs.

arXiv · eess.SYConceptual

Potentials and Limitations on Different Busbar Protections in Industrial Applications

Why a 2022 blackout in Taiwan reveals gaps in how factories protect their power switchgear.

Big industrial facilities rely on busbars — the thick metal bars that distribute electricity throughout a plant — and if something goes wrong there, protective systems need to instantly detect and isolate the fault before it cascades into a wider blackout. Taiwan's 2022 '303 blackout' showed what happens when these protections aren't well designed: a short circuit combined with a monitoring failure caused a huge outage. This paper reviews and compares the different busbar protection schemes available today, from simple overcurrent detection to modern digital systems, weighing their real-world strengths and weaknesses like sensor placement and false-trip risks. The goal is to give engineers practical guidance so industrial power grids are less likely to suffer these kinds of cascading failures.

Technical view

The paper surveys busbar protection (BBP) schemes — leakage-to-frame, high-impedance differential (87Z), interlocking overcurrent (ILOC), electronic (EBBP), and numerical (NBBP) — evaluating their practical limitations in industrial settings, motivated by the 2022 Taiwan '303 blackout' caused by a fault combined with CT (current transformer) supervision lockout. It addresses design challenges including CT placement and saturation, dynamic protection zone selection, and evolving fault scenarios not well captured by existing standards. The analysis is a structured comparative evaluation rather than a novel algorithm, giving protection engineers criteria for selecting a BBP scheme suited to their CT infrastructure and fault-tolerance requirements. This is directly applicable to substation and switchgear protection design reviews.

arXiv · physics.ins-detConceptual

On a Liquid Krypton TPC for double positron decay searches

Hunting an ultra-rare nuclear decay by catching four gamma rays at once in liquid krypton.

Physicists are searching for an exotic, extremely rare radioactive decay called double positron decay, where a nucleus emits two positrons (antimatter electrons) that each annihilate with a normal electron, producing four telltale gamma rays. Because this exact four-gamma signature is essentially impossible to fake with ordinary background radiation, catching all four at once would be near-proof of the decay. The researchers propose a detector — a time projection chamber filled with liquid krypton — that can track particle trails and tag all four gammas simultaneously. Scaled up to about a ton of krypton, this detector could set the best-ever limit on how rare this decay is, probing timescales of a billion billion billion years or more.

Technical view

Double positron (β+β+) decay produces four coincident 511 keV annihilation gammas alongside a characteristic 'double blob' track topology, offering a near-background-free signature when all four photons are tagged in coincidence. The authors propose a liquid krypton TPC (time projection chamber) exploiting this four-gamma tagging to suppress backgrounds essentially to zero. They estimate that even a modest-scale prototype could improve on existing limits, with a ton-scale detector projected to reach sensitivities of 10^29–10^30 years for the decay half-life, a substantial improvement over current bounds. This establishes liquid krypton TPCs as a candidate technology for next-generation rare-event searches, worth pursuing via prototype R&D on gamma tracking and coincidence tagging efficiency.

arXiv · eess.SYBuildable

Input-to-state Stable Approximate Nonlinear Model Predictive Control with Realtime Feasibility

A lightweight control algorithm keeps spacecraft stable in real time even when models are imperfect.

When a robot or spacecraft needs to plan its next moves in real time, it typically uses model predictive control — repeatedly solving a math puzzle that predicts a few steps ahead and picks the best safe action given constraints like fuel limits or collision avoidance. Doing this exactly is often too slow for cheap onboard computers, especially when the system's behavior isn't perfectly known or gets disturbed by outside forces. This paper introduces a streamlined version that only needs to solve small, fast optimization problems while still mathematically guaranteeing the system won't spiral out of control under disturbances or model imperfections. Tested on simulated spacecraft control tasks, it matches or beats other robust control methods while being cheap enough to run on real embedded hardware.

Technical view

The paper proposes an approximate robust nonlinear MPC (model predictive control) scheme combining an input-to-state control Lyapunov function with a robust control barrier function, extending a prior nominal infinitesimal-horizon NMPC formulation that reduces online computation to small quadratic programs solvable on embedded hardware. The ISS (input-to-state stability) guarantee bounds state error under bounded disturbances or model mismatch without requiring the full nonlinear MPC optimization at each step. Numerical experiments on nonlinear constrained spacecraft control show performance competitive with existing robust NMPC methods from the literature at a fraction of the computational cost. Control practitioners working on real-time embedded nonlinear control, such as aerospace or robotics, could adopt this QP-based scheme where full NMPC is infeasible.

FIN

HFT & Quant Finance

2 new
arXiv · cs.CEBuildable★ flagship

Train Often, Deploy Selectively: Forward-Gated Model Replacement in Crypto Markets

Don't swap your live trading model on a schedule—only if a shadow challenger actually proves it's better.

Companies that forecast things (like crypto prices) routinely retrain their models and swap the fresh one in, assuming newer is better—but a retrained model isn't guaranteed to beat the one that's been quietly learning on the job the whole time. This paper proposes a rule called 'Shadow Before Swap': train a challenger model off to the side, let both the challenger and the current champion predict the same upcoming week, and only promote the challenger if it beats the champion by a clear, fixed margin. They tested it on nearly a year of real Binance crypto-futures data across many coins and setups. The payoff is small in percentage terms but consistent: fewer bad forecasts than swapping on the calendar, than auto-promoting, or than just continuously maintaining one model. The lesson is broadly useful—retrain often, but deploy conservatively, gated on measured evidence rather than a schedule.

Technical view

Shadow Before Swap (SBS) warm-refits a challenger off the serving path and promotes it only after it beats the maintained incumbent by a fixed paired negative-log-likelihood (NLL) advantage evaluated on the same next week of delayed labels. In historical replay over two nonoverlapping Binance episodes (48 UTC weeks, 3 seeds, 8 underlyings, 2 perpetual-futures contract types), SBS cut NLL by 0.1472% vs calendar replacement, 0.0755% vs schedule-matched automatic promotion, and 0.0428% vs continuous maintenance, with episode-stratified four-week block confidence intervals reported. The mechanism is a paired, delayed-label statistical gate rather than a fixed cadence, framing model deployment as a hypothesis test on incremental predictive log-loss. Practitioners can adopt the pattern for any regularly retrained probabilistic forecaster: maintain an incumbent, shadow-evaluate challengers on identical held-out labels, and promote only past a preset NLL threshold.

arXiv · cs.CEBuildable

Can Large Language Models Execute Parent Orders?

Can chatbots be trusted to slice up a giant stock trade without tipping off the market?

When a big investor wants to buy or sell a huge chunk of stock, dumping it all at once would crash the price, so trading firms break the order into many small pieces spread over time, a task called execution. Traditionally this requires either rigid rule-of-thumb formulas or specially trained trading algorithms that don't adapt well to new situations. This paper asks whether general-purpose AI language models, like the ones behind chatbots, can handle this job instead, and introduces PACE, a system where the AI first makes a long-term plan for spreading out the trade, then makes quick short-term decisions about individual small orders. Tested on real Chinese stock exchange data, PACE beat standard benchmark strategies, suggesting language models might be a flexible new tool for trading execution without needing custom training for every market.

Technical view

The paper studies LLMs for parent-order execution, splitting a large order into child orders to minimize market impact and cost, an area previously dominated by hand-specified strategies like TWAP and Almgren-Chriss or task-specific trained RL/ML models. PACE (Plan-Ahead Controlled Execution) is a hierarchical framework where an LLM performs long-horizon planning of the order-splitting schedule and separately handles short-horizon execution decisions, requiring no explicit market microstructure assumptions or fine-tuning. On Shenzhen Stock Exchange Level-1 order book data, PACE outperforms TWAP, Almgren-Chriss, and unspecified learning-based baselines. This suggests LLM-based hierarchical planning is a viable zero-shot alternative to custom-trained execution algorithms, and practitioners could replicate the plan/execute decomposition with off-the-shelf LLMs plus market data feeds.

PHY

Physics

40 new
arXiv · hep-thConceptual★ flagship

Learning to Trace Seiberg Dualities

Can a neural network learn to prove two exotic physics theories are secretly the same?

In physics, a 'duality' means two theories that look totally different on paper actually describe the same underlying reality — like two maps of the same city drawn in different styles. Seiberg duality is a famous example among certain super-symmetric particle theories, but checking whether two given theories are really dual can be a grinding, complicated calculation. This paper trains machine-learning models to spot and carry out those transformations automatically, treating them as a puzzle of reshaping mathematical diagrams called 'quivers' (dot-and-arrow graphs that encode a theory). It's closely related to the well-known challenge of teaching AI to tell whether a tangled loop is really a knot. The payoff is twofold: a practical tool for measuring how hard each duality is to verify, and a window into how different AI architectures actually reason their way through the problem.

Technical view

The authors cast the verification of Seiberg dualities for supersymmetric quiver gauge theories as a sequence of quiver mutations, structurally analogous to the 'learning to unknot' reinforcement-learning problem. They apply and compare neural architectures that learn to trace mutation paths connecting dual quivers, using the learned policies as a probe of the computational complexity of establishing a given duality. Beyond a usable classification/search tool, the work offers an interpretability angle — how architecture choice affects the model's ability to discover valid mutation sequences. A practitioner could adapt knot-theory RL pipelines (state = quiver adjacency data, actions = mutations) and benchmark architectures on duality-tracing tasks.

arXiv · cond-mat.str-elBuildable

Graph Neural Network Force Fields for Spin Dynamics in Metallic Magnets

AI learns to fast-forward magnet simulations that used to need slow quantum recalculations.

Metallic magnets have 'itinerant' electrons — ones that roam freely through the metal — and these electrons are what generate the interactions steering how the magnet's internal spins (tiny magnetic arrows) swirl and evolve over time. Simulating this normally means re-solving a full quantum electronic-structure problem at every single time step, which is brutally slow. Here, researchers train a graph neural network (a model that treats atoms as connected nodes and passes information along the connections) to directly learn the 'energy rulebook' spins are following, sidestepping the repeated quantum calculations, much like how machine-learned potentials already speed up atomic-motion simulations. This matters because it could make simulating exotic magnetic patterns fast enough to actually design better magnetic memory and spintronic devices.

Technical view

The GNN learns an effective magnetic energy functional from electronic-structure (DFT-type) calculations, conceptually mirroring machine-learned interatomic potentials (e.g., NequIP/MACE) but for spin torques instead of atomic forces. This lets it capture the nonlinear, spatially extended, itinerant-electron-mediated interactions (RKKY-like) without repeated self-consistent electronic solves during time evolution. It's benchmarked across collinear, noncollinear, and noncoplanar spin textures in representative metallic magnets, reproducing dynamics that would otherwise require full electronic recalculation at each step. Practitioners could adapt the message-passing architecture and training pipeline to accelerate atomistic spin-dynamics codes for spintronic device design.

arXiv · astro-ph.HEConceptual

A Four-dimensional Model-agnostic Probe into the Astrophysical Origins of Binary Black Hole Subpopulations

Astronomers map hidden 'family trees' of merging black holes without assuming how they formed.

Detectors like LIGO and Virgo pick up gravitational waves — ripples in spacetime — from pairs of black holes spiraling together and merging. Scientists suspect these events come from several distinct 'families,' formed through different cosmic pathways (say, stars that evolved together versus black holes that met by chance in dense star clusters), but pinning down these families is hard: methods that assume a specific formation theory risk just confirming that theory, while flexible, theory-free methods tend to break down or lose important patterns once you look at many properties at once. This paper builds a flexible, data-driven map of four black-hole properties simultaneously, letting the actual observed data reveal the population structure rather than baking in assumptions upfront. This gives astrophysicists sharper, less-biased clues about how these black-hole pairs actually form.

Technical view

The authors present the first flexible, non-parametric reconstruction of the joint four-dimensional distribution of binary black hole population parameters (from the LVK gravitational-wave catalog) that avoids both the prior-driven bias of strongly parametric population models and the dimensionality-scaling failures of typical model-free approaches that discard cross-parameter correlations. By preserving correlations across four dimensions simultaneously, the reconstruction can reveal astrophysically meaningful joint structure (e.g., mass/other-parameter correlations tied to distinct formation channels) that lower-dimensional or single-parameter analyses would miss. This is directly usable by population-synthesis modelers to stress-test formation-channel predictions against correlated structure in the real catalog rather than marginal distributions alone.

arXiv · quant-phConceptual

Lifting Lifted Product Codes

A new recipe scales up quantum error-correcting codes without losing their easy-to-build structure.

Quantum computers are extremely sensitive to noise, so they rely on special error-correcting codes to protect fragile quantum information; 'lifted product' codes are a strong existing family of these. This paper introduces a systematic way to 'lift' these codes into larger, better versions using group extensions and graph lifts — mathematical tools for growing a structured network while keeping its local, manageable wiring pattern intact. The bigger codes they produce outperform previously known versions, and crucially, the special operations used to manipulate encoded quantum information ('code surgery,' used to implement logical gates) can be carried over to the larger codes efficiently, sometimes even more cheaply. This is a step toward larger, more practical fault-tolerant quantum computers.

Technical view

The construction builds families of lifted product (LP) codes via group extensions and graph lifts applied to the Tanner graph, preserving local (low-density) structure while relating code parameters, logical operators, and fault-tolerant logical gadgets across the family through chain and cochain maps. The authors report LP codes with improved parameters over previously known constructions, show that code-surgery gadgets transfer across finite lifts via chain maps (with lower space overhead in several cases), and develop a parallel product surgery scheme for lifted clustered cyclic codes. Quantum LDPC code designers could use this lifting framework as a systematic route to scale up code families while reusing already-designed logical gate implementations rather than re-deriving them from scratch.

arXiv · hep-phConceptual

Improved Approximations for Collective Neutrino Oscillations

A smarter math shortcut lets normal computers approximate the quantum dance of trillions of neutrinos.

When huge numbers of neutrinos (ghostly subatomic particles) interact, as they do inside supernovae, they can collectively swap their 'flavor' identities in a complex quantum dance that's far too computationally expensive to simulate exactly. This paper studies the underlying mathematical structure of the equations governing that dance and applies a technique borrowed from statistical physics, called BBGKY hierarchy truncation, which approximates the full many-body system by tracking correlations a few particles at a time instead of all at once. The payoff is a systematic way to go beyond the crude 'average everyone together' (mean-field) approximation while keeping the computation manageable — growing only polynomially rather than exploding — on an ordinary classical computer. This gives astrophysicists a more accurate but still affordable tool for modeling neutrino behavior in supernovae and the early universe.

Technical view

The authors analyze the su(n) algebraic structure (embedded within u(n^N)) of the one- and two-body Hamiltonian governing collective neutrino oscillations, deriving a product structure of the algebra that yields generic closed-form expressions for operator expectation values, Rényi entropy, and Wigner functions. Applying BBGKY hierarchy truncation to this structure, they construct a systematic hierarchy of approximations that extend beyond mean-field theory while keeping classical computational cost polynomial rather than exponential in system size. This gives supernova and early-universe neutrino transport codes a tractable route to include beyond-mean-field correlation corrections without resorting to full exponential-cost many-body simulation.

arXiv · hep-phConceptual

Why 4D? Spontaneous Dimensional Selection from Gauge Criticality

A physics idea suggests the universe has exactly 4 dimensions because that's the one 'balanced' choice for how forces behave.

Forces like the strong nuclear force get stronger at long distances if space has fewer than 4 dimensions, fade away with more than 4, and sit at a perfectly balanced tipping point exactly at 4 — physicists call this a 'critical' point. The author proposes this special balance is exactly why our universe ends up with 4 big dimensions instead of some other number: extra dimensions could shrink down to nothing unless the tipping point locks them in place. As a working example, they build a concrete toy model (a 'racetrack,' a known trick from string theory for stabilizing the size of hidden extra dimensions) without assuming 4D from the outset. The extra dimensions naturally settle at a size corresponding to ordinary 4D spacetime, driven by this force-balance effect together with a form of symmetry-breaking called supersymmetry breaking. It's a step toward explaining 'why 4 dimensions?' from physics rather than just observing it.

Technical view

Uses renormalization-group scaling of the Yang-Mills coupling — relevant below 4D, marginal at 4D, irrelevant above 4D — to argue 4D is an IR-critical dimensionality. Builds an explicit racetrack superpotential model (multiple gaugino condensates) generating a radion potential, where gauge-criticality-induced SUSY breaking plus supergravity corrections stabilize the radion at a value corresponding to noncompact 4D spacetime, without presupposing 4D at the outset. Serves as a proof-of-principle mechanism that could be extended with different gauge groups/matter content or connected to swampland/landscape selection arguments.

arXiv · quant-phBuildable

Learning Arbitrary Lindbladians from Time Evolution

A new algorithm reverse-engineers the hidden noise and dynamics rules of a quantum system just by watching it run.

A Lindbladian describes how a 'leaky' quantum system evolves when it's exchanging energy or information with its surroundings, including both its clean quantum behavior and its noisy, dissipative side. Figuring out these rules from scratch is hard because there are exponentially many possible ingredients that could be present. The authors design an efficient algorithm that pins down every one of these hidden values accurately, just by evolving the system for set amounts of time and measuring it — no extra helper qubits or elaborate control needed. It works in two simple, one-shot stages: first narrowing down which pieces matter, then measuring them precisely. This matters because it gives a practical, low-overhead way to diagnose noise and dynamics on real quantum hardware.

Technical view

Proposes a non-adaptive, ancilla-free, control-free algorithm for learning an unknown Lindbladian generator (Hamiltonian plus dissipative Pauli-indexed coefficients) purely from time-evolved measurement statistics. For dynamical strength bound Λ, it estimates each coefficient to error ε using Õ(Λ²/ε²) experiments and Õ(Λ/ε²) total evolution time, with polynomial classical post-processing. A support-learning stage first isolates a poly(Λ/η)-sized candidate set containing every coefficient of magnitude ≥η, feeding a subsequent estimation stage. Directly applicable to characterizing noise/dissipation on real quantum devices without entangling ancillas, making it practical for near-term hardware benchmarking and calibration.

arXiv · quant-phBuildable

Logical computation with canonical lifted product codes

A new code design packs many protected qubits tightly while still letting you compute on them efficiently.

Quantum computers need error-correcting codes to shield fragile qubits from noise, and 'high-rate' codes are attractive because they protect many logical qubits per physical qubit used. The catch is that generic ways of running computations on such densely packed codes tend to be clunky or hard to verify. This paper designs the error-correcting code and its set of computational instructions together, focusing on a family called 'lifted product codes' that have a repeating, cyclic structure. They find a natural, organized way to arrange the protected qubits — a 'canonical logical basis' — that mirrors the tidy patterns of the simpler classical codes underneath, making operations on them far more manageable. This matters because it's a concrete step toward making large, efficient, fault-tolerant quantum computers practical to build.

Technical view

Addresses the tension between high-rate qLDPC codes' physical-qubit efficiency and the difficulty of realizing modular, low-overhead fault-tolerant logic (code surgery, gate teleportation) on their otherwise unexploited structure. Co-designs canonical lifted-product (LP) codes with cyclic symmetry alongside a matching logical instruction set, revealing a canonical logical basis where conjugate logical operator pairs organize into rows/columns of cyclic orbits inherited from the underlying classical codes — analogous to hypergraph-product code structure. This gives a systematic, certifiable route to fault-tolerant logical gates on high-rate LP codes for anyone designing near-term qLDPC-based fault-tolerant architectures who wants structured rather than ad hoc logical operations.

arXiv · astro-ph.CORunnable

Cosmo-SPINN: Fuzzy Dark Matter Simulations with Physics-Informed Generative Networks

An AI is taught the real equations of dark matter physics, not just trained to fake realistic-looking simulations.

Fuzzy dark matter is a theory where dark matter behaves like a giant quantum wave rather than clumps of particles, and simulating how it evolves across cosmic history is extremely computationally expensive. This work builds an AI model — a physics-aware generative neural network — that can both fast-forward these simulations to any point in cosmic time and sharpen the detail of low-resolution simulations. The key trick is that instead of just learning to mimic realistic-looking outputs, the AI is explicitly trained to obey the real physical equations (the Schrödinger-Poisson equations governing how the dark-matter wave moves and pulls on itself with gravity). This physics-aware training measurably makes its predictions more faithful to real physics than AI trained without it. It matters because it could make simulating alternative dark matter theories dramatically cheaper, helping test them against real astronomical observations.

Technical view

Introduces a physics-informed generative U-Net for fuzzy dark matter (FDM) simulations handling two tasks: evolving cosmological fields from initial conditions to an arbitrary scale factor, and super-resolving low-resolution FDM snapshots. The core contribution is a physics-informed loss term enforcing consistency with the governing Schrödinger-Poisson (SP) equations during training, rather than relying solely on data-driven generative objectives. Results show this physics-informed loss significantly improves adherence to SP dynamics for the evolution task compared to baselines lacking it. Functions as a fast drop-in emulator/upsampler for FDM simulation pipelines, and the physics-informed loss design is transferable to other PDE-constrained generative cosmological emulators.

arXiv · quant-phConceptual

Pauli Encodings & Unclonable Encryption

Researchers test whether quantum encryption can truly stop a spy from cloning a secret before the key gets revealed.

The 'unclonable bit' question asks whether you can encrypt a single bit using quantum physics so nobody can create two separate copies that both later reveal the message once the decryption key is made public — quantum mechanics' no-cloning rule should, in principle, help block this. The authors study a simple family of such schemes called Pauli Encodings, built from basic quantum measurement operations known as Pauli strings. They prove mathematical limits on how well an adversary can be stopped from cheating, and show that some versions of these schemes — like ones restricted to a narrower toolkit of operations — are actually insecure. They also show that a whole common strategy for proving these schemes secure has a fundamental blind spot that keeps it from ever fully succeeding. This matters for anyone trying to build trustworthy 'copy-proof' quantum encryption.

Technical view

Formalizes Pauli Encodings — one-bit encryption schemes whose ciphertexts are eigenspace projectors of Pauli strings — and analyzes their unclonable-encryption security through the monogamy-of-entanglement (MoE) game framework. Proves a universal lower bound of 1/2 + 1/(2√K) on optimal MoE winning probability for K-Pauli-string schemes, with tighter bounds for structured subfamilies, and shows encodings restricted to X/Z-only Pauli strings of length n are provably insecure. Also establishes a universal 3/4 obstruction proving that security arguments based solely on pairwise adversary-guessing marginals cannot establish full unclonable-indistinguishability, ruling out an entire class of proof techniques. Gives cryptographers concrete bounds and no-go results to design around when building or analyzing Pauli-based unclonable encryption or copy-protection schemes.

arXiv · quant-phRunnable

SymFT: Universal Fault-Tolerant Quantum Circuit Simulation via Symbolic Clifford--Pauli Frames and Stabilizer Coordinates

A faster simulator lets researchers stress-test huge quantum error-correcting circuits on ordinary computers first.

Fault-tolerant quantum computing protocols are mostly built from simple, cheap-to-simulate 'stabilizer' operations, but they also need a few special extra operations to be fully general-purpose, and those are expensive to simulate honestly. SymFT is a new simulator that handles these mostly-simple circuits — including their noise, mid-run measurements, and measurement-based corrections — much faster than before. Its trick is tracking the mathematical structure of the operations symbolically instead of re-simulating every random outcome from scratch, and only storing the parts of the quantum state that are actually changing rather than the whole thing. This matters because it lets researchers cheaply test-drive large fault-tolerant quantum circuit designs on ordinary computers before running them on real, expensive, error-prone quantum hardware.

Technical view

SymFT is a high-throughput classical simulator for Clifford-dominated fault-tolerant circuits containing Pauli rotations, stochastic Pauli noise, mid-circuit Pauli measurements, and measurement-conditioned Pauli feedback. It combines symbolic Clifford-Pauli frame factorization, which reduces per-shot branch-probability sampling to just the Pauli rotations and measurement projectors (since the unitary Clifford/Pauli-frame parts don't affect branch probabilities and need not be applied every shot), with adaptive stabilizer-coordinate planning, which uses a shared stabilizer-destabilizer tableau and stores only the dynamically active non-stabilizer degrees of freedom. This should yield substantial speedups over naive stabilizer-plus-magic-state simulators for large-scale fault-tolerant circuit benchmarking, directly useful for validating QEC protocol designs before hardware deployment.

arXiv · astro-ph.COConceptual

Axion Inflation with a Massive Abelian Gauge Field

A heavy 'magnetic' field during cosmic inflation can quietly brake the universe's early expansion.

During the earliest fraction of a second after the Big Bang, a field called the inflaton drove the universe's exponential expansion, and theorists like to check what happens if it's coupled to invisible force fields similar to electromagnetism. Here the researchers add mass to that force-carrying field and find that only when a coupling strength parameter is bigger than the field's mass (relative to the expansion rate) does the field get dramatically amplified, borrowing energy from the inflaton and slowing it down like friction. Because the amplified ripples stay compressed into small, non-cosmic scales when the mass is large, they barely leak into the large-scale patterns we could observe in the sky. The payoff is a formula showing exactly how that leaked signal shrinks as the mass grows, giving cosmologists a dial for how much extra structure an unseen massive field could imprint on the universe.

Technical view

This extends the well-known axial inflaton-gauge coupling ('ξ' controls tachyonic amplification of one helicity) to a massive Abelian vector field, showing the instability threshold shifts to |ξ|>m/H≡m̄, with amplitude scaling as exp[π(|ξ|-m̄)] in the heavy regime rather than the massless exp(π|ξ|). Because amplified modes stay sub-Hubble for m̄≫1, their sourcing of curvature perturbations ζ is power-law suppressed, yielding P_ζ^id ∝ m̄^{-2} in the weak-backreaction limit. A practitioner modeling axion-gauge inflation or gauge-field friction mechanisms (e.g., for non-Gaussianity or gravitational-wave signatures) can use this scaling to bound how much a massive spectator vector could contaminate CMB/LSS observables versus contribute unobservable friction.

arXiv · hep-phConceptual

LISA Reconstruction Landscape for Metastable Cosmic Strings

Space-based gravity-wave detectors could catch cosmic strings 'popping' apart and read off their properties.

Cosmic strings are hypothetical ultra-thin defects left over from the early universe, like cracks frozen into the fabric of space, and 'metastable' ones can eventually break apart via a quantum tunneling process that spits out pairs of monopoles (magnetic point-like defects). This study asks whether the future LISA space gravitational-wave observatory could detect the background hum of gravitational waves these decaying strings produce, and more importantly, whether it could figure out the strings' properties (like tension and decay rate) from the shape of that hum. The team simulates fake LISA data, complete with realistic instrument noise and other background gravitational-wave clutter, then uses Bayesian statistics (a method for updating what you believe based on evidence) to see how well the string parameters could be pinned down. The result is a map of exactly when you'd merely detect 'something's there' versus when you could actually reconstruct the physics behind it.

Technical view

The paper models the stochastic gravitational-wave background from metastable cosmic strings that decay via zero-temperature nucleation of monopole pairs, which truncates loop production after a lifetime set by the breaking rate κ_CS, producing an IR spectral tail and a transition to a stable-string plateau at high frequency. Using synthetic LISA data including instrument noise and unresolved astrophysical foregrounds, they perform Bayesian parameter estimation in the (Gμ, κ_CS) plane to map detectability, parameter correlations, and degeneracies. This gives a template for distinguishing mere background detection from full spectral reconstruction, directly useful for LISA science-case forecasting of cosmic-string or other metastable-defect scenarios.

arXiv · quant-phRunnable

Benchmarking Quantum Simulations of the Lipkin-Meshkov-Glick Model Using Large Tensor Networks

Classical supercomputers still crush today's quantum computers at a 1400-particle physics benchmark.

To know if quantum computers are actually useful yet, you need a fair fight against the best classical (regular) computer methods on the same problem. Here researchers pick the Lipkin-Meshkov-Glick model, a simplified stand-in for how particles in a nucleus interact, and compute its lowest-energy state using a powerful classical technique called DMRG on one of the world's fastest supercomputers, scaling up to 1400 particles — a huge benchmark dataset. They then compare that gold-standard answer to two popular near-term quantum algorithms (VQE and SQD) run on an actual IBM quantum chip with only a handful of particles. The takeaway is a concrete, numeric scoreboard of how close (or far) today's noisy quantum hardware is from matching classical methods, which helps set realistic expectations for quantum computing's near future.

Technical view

The authors run DMRG (Density Matrix Renormalization Group, a tensor-network method) on NERSC's Perlmutter supercomputer to generate ground-state energies of the LMG model for systems up to 1400 particles, producing one of the largest such benchmark datasets to date. They compare against VQE and Sample-Based Quantum Diagonalization (SQD) executed on an IBM Eagle quantum processor, finding VQE within 1% error only at 6 particles before error growth at scale. This gives practitioners a concrete classical-vs-NISQ error/scaling baseline for LMG-type collective spin models, useful for calibrating expectations and designing better ansätze or error-mitigation strategies for near-term quantum hardware.

arXiv · nucl-thConceptual

Relativistic transport near moving interfaces

One math trick unifies boat wakes, shock-wave tails, and heat fronts — even at near-light speeds.

When something moves through a medium at constant speed — a boundary, an obstacle, a heat source — it leaves a disturbance pattern behind it, like a boat's wake or the trailing edge of a shock wave. This paper works out the physics of these disturbances when the medium and its motion are relativistic (following Einstein's rules, relevant for things like plasmas near black holes or heavy-ion collisions). The key trick is a mathematical tool (a Laplace transform, which turns wiggly signals into simpler frequency components) that reveals every possible disturbance pattern as points sitting on a single sweeping line in an abstract 'frequency vs. wavenumber' plot, with the line's angle set by the speed. As the speed changes, that line sweeps across, and where it crosses lets you read off exactly what pattern of waves and tails will form — a single unified geometric picture for wakes, boundary layers, and shock tails.

Technical view

The paper analyzes linear perturbations near planar interfaces moving at constant velocity v in relativistic media, covering moving obstacles, thermal boundaries, and external sources within one formalism. Using a Laplace-transform approach, they derive a propagator representation showing the interface solution decomposes into modes with purely imaginary frequency and wavenumber, selected by the line iω = vik in the (iω, ik) complex plane; sweeping v across this line geometrically classifies all interface-localized responses. This gives a practitioner a general recipe for computing wake and boundary-layer profiles (and shock-tail asymptotics) in relativistic hydrodynamic or kinetic theories directly from the medium's dispersion relation, without solving the full PDE case-by-case.

arXiv · astro-ph.COConceptual

Dark Matter Constraints from Small-Scale Cosmic Structure

The universe's smallest structures are quietly ruling out entire families of dark matter theories.

We don't know what dark matter — the invisible stuff making up most of the universe's mass — is actually made of, but different candidate theories (like 'warm,' 'fuzzy,' or self-interacting dark matter) predict different amounts of clumping on very small cosmic scales. This review rounds up how astronomers use tiny, faint dwarf galaxies, gravity's light-bending (lensing), the pattern of gas absorbing quasar light (the Lyman-alpha forest), streams of stars torn from small galaxies, and even the earliest galaxies ever seen, to measure exactly how clumpy matter is below roughly 3 million light-years. Because each dark matter model leaves a distinctive fingerprint on that clumpiness, matching or mismatching these observations lets scientists rule in or rule out specific theories about what dark matter's basic particle physics could be.

Technical view

The review synthesizes constraints on dark matter microphysics — free-streaming suppression (warm DM), wave interference/quantum pressure (fuzzy DM), and self- or DM-SM interactions — using nonlinear structure below ~1 Mpc as the discriminating regime. It surveys how dwarf galaxy counts/internal structure, strong lensing substructure, the Lyman-α forest power spectrum, stellar stream perturbations, and high-z galaxy abundances each translate into bounds on parameters like DM particle mass, cross-section, or interaction strength. For a practitioner, it's a current reference map of which small-scale observable is most constraining for which DM model class, useful for prioritizing which datasets or simulations to target next in testing non-CDM scenarios.

arXiv · quant-phConceptual

Statistically secure uncloneable encryption of arbitrary messages

A new encryption scheme lets you send any-length secret messages that are physically impossible to copy.

Uncloneable encryption is a wild idea from quantum cryptography: because of quantum mechanics' no-cloning rule, you can encrypt a message so that even someone who steals the encrypted data can't make a usable copy of it, unlike regular encrypted files which can always just be copied bit-for-bit. Until now this trick only reliably worked for a single bit of information with the strongest ('statistical,' meaning provably secure even against unlimited computing power) security guarantee. This paper shows how to stretch that single-bit trick to messages of any length while keeping the same rock-solid security guarantee, by cleverly reusing a special set of quantum operations (Clifford unitaries, a well-behaved family of quantum gates) that the single-bit version already relied on. The result matters because it turns a neat proof-of-concept into something that could actually protect real, longer messages from being copied — useful for things like un-copyable digital cash or licenses.

Technical view

Building on a known single-bit uncloneable encryption scheme whose security proof relies on encoding bases drawn from a subset of Clifford unitaries, the authors extend the construction to arbitrary-length messages while preserving unconditional (information-theoretic) security, with encoding time polynomial in message length and security parameter. This closes an open question about whether statistical security survives the single-bit-to-many-bit generalization for uncloneable encryption. Cryptographers building quantum-secure primitives (uncloneable currency, copy-protected software/licenses) can now use this as a drop-in scheme for protecting multi-bit payloads without falling back to computational (rather than statistical) security assumptions.

arXiv · hep-phConceptual

Three Texture Zeros in the Hermitian Dirac sector within Type-I Seesaw Mechanism

Simple zero-patterns in an elusive particle's mass math still fit real neutrino data.

Neutrinos are ghostly particles whose tiny masses are one of physics' biggest puzzles, and the 'seesaw mechanism' is a popular idea explaining why they're so light by pairing them with very heavy, undiscovered partner particles. This paper tests a simplifying assumption — that the mathematical matrix describing how neutrinos get their mass has certain entries forced to exactly zero ('texture zeros') and is otherwise symmetric in a particular technical sense (Hermitian) — to see if it can still match real experimental measurements of neutrino behavior. By plugging in numbers and checking against the NuFIT global dataset (the standard compilation of world neutrino experiment results), they find several specific zero-patterns that work for both possible orderings of neutrino masses (normal and inverted). This matters because it narrows down which mathematical structures for the neutrino mass matrix are still viable candidates for the true underlying theory.

Technical view

Working within the type-I seesaw mechanism with a diagonal heavy Majorana mass matrix, the authors impose Hermiticity plus three texture zeros on the light Dirac mass matrix and numerically scan for benchmark solutions consistent with neutrino oscillation data. They identify four viable texture patterns under normal ordering and three under inverted ordering that reproduce mixing angles and mass-squared differences within 3σ of the NuFIT global fit. This provides concrete, falsifiable Yukawa-matrix ansätze that model-builders can use as starting points for constructing seesaw models with reduced parameter counts, testable against future precision neutrino oscillation and 0νββ (neutrinoless double beta decay) data.

arXiv · hep-thConceptual

Soft charges and zero modes at null boundaries

Even empty space at a black hole's edge hides a subtle, overlooked charge.

Physicists study 'null boundaries' — special edges of spacetime like the outer horizon of a black hole or the far edge of the universe — because they carry hidden conserved quantities, similar to how charge or energy is conserved. This paper points out that these boundaries have an extra, previously under-examined freedom (a 'zero mode', basically an overall shift that doesn't change the local physics but does change bookkeeping). The authors show this zero mode isn't just a mathematical nuisance: it produces a genuine new measurable quantity living right at the edge, and it changes how these conserved charges combine with each other. The result applies broadly, whether the edge is at the boundary of the universe or the horizon of a black hole, refining our understanding of information and symmetry at these boundaries.

Technical view

The paper analyzes the covariant phase space of field theories on null boundaries and isolates a global zero-mode ambiguity distinct from the residual gauge (BMS-like) transformations usually studied. They show this zero mode modifies the symplectic/canonical structure, producing a new quasilocal edge observable that enters and deforms the charge algebra (central extensions/non-trivial brackets). The construction is general, applying uniformly to null infinity and finite-distance null surfaces like black hole horizons, suggesting implications for holographic charge algebras and horizon entropy bookkeeping.

arXiv · quant-phBuildable

A Provable Oracle-Free Quantum Algorithm for Nonlinear Dynamics on Hybrid Oscillator-Qubit Processors

A quantum computer trick lets you solve messy nonlinear equations without lookup tables.

Many real-world systems — weather, chemical reactions, population dynamics — are described by nonlinear equations that are notoriously hard to solve exactly, especially on quantum computers, which usually need cumbersome 'oracle' subroutines to plug in the nonlinear math. This work builds a hybrid quantum computer that combines regular qubits with 'qumodes' (a different kind of quantum unit that behaves like a continuous wave) to sidestep that requirement entirely. Their approach follows the trick of tracking not a single answer but a whole cloud of probabilities that narrows down to the true trajectory, and cleverly encodes the equation's complexity so it can be processed efficiently with quantum hardware. The payoff is a mathematically provable, oracle-free method for simulating nonlinear systems — a capability many thought would remain a major bottleneck for quantum computing.

Technical view

The authors present a hybrid qubit-qumode algorithm for polynomial-degree nonlinear ODEs, using the Fokker-Planck/warped-phase-transformation route (Tennie-Magri, Jin-Liu-Yu) to recast nonlinear dynamics as a linear Schrödinger-type evolution, with the added Fourier-mode parameter placed on a continuous-variable qumode rather than requiring additional qubits or oracles. Their key structural result is a bipartite Pauli decomposition of the discretized generator's Hermitian parts into O(log N) mutually commuting families, each further factorized via local positive-semidefinite decomposition — enabling efficient Hamiltonian simulation. This gives a provably correct, oracle-free circuit construction that practitioners could implement on emerging hybrid CV-DV (continuous-variable/discrete-variable) hardware for nonlinear dynamical simulation.

arXiv · astro-ph.HERunnable

Search for gravitational waves associated with high-energy neutrinos detected by IceCube during the third observing run of LIGO-Virgo

Detectors listened for gravitational-wave echoes from cosmic neutrino events — and heard nothing new.

When IceCube, a detector buried in Antarctic ice, spots a high-energy neutrino, scientists wonder if it came from a violent cosmic event that also shook spacetime itself, producing gravitational waves. This study cross-checks IceCube's neutrino detections against data from the LIGO, Virgo, and KAGRA gravitational-wave observatories during their third major observing run, using a technique that doesn't assume a specific type of event, making it more sensitive to fainter signals. They found no gravitational-wave signal matching any neutrino detection this time, but the search itself is valuable: it can catch weaker overlapping signals that routine follow-up searches would miss. From the non-detection they calculated how far away compatible sources would have to be to still evade detection, tightening constraints on multi-messenger astrophysics.

Technical view

The study performs an unmodeled (generic burst) coincidence search between IceCube high-energy neutrino alerts and gravitational-wave strain data from Advanced LIGO/Virgo/KAGRA's O3 run, targeting weaker joint signals below the sensitivity of standard real-time or catalog-based follow-up. No statistically significant coincident gravitational-wave signal was found. The null result is translated into distance exclusion limits for candidate joint emission models (e.g., core-collapse or compact object mergers with neutrino production), providing updated multi-messenger sensitivity benchmarks that future searches or population studies can build on.

arXiv · quant-phConceptual

When quantum thermal states look classical

Hot quantum systems fake being simple — until a precise temperature where quantumness suddenly kicks in.

Quantum systems at very high temperature behave almost like classical random noise: no entanglement (spooky quantum correlations), no 'magic' (a technical resource that makes quantum computers powerful), and they're easy to simulate on ordinary computers. This paper asks: how cold can you make such a system before it starts acting distinctly quantum again? The authors prove precise temperature thresholds — not just one, but several — at which different classical-looking properties break down one by one, forming an orderly hierarchy of transitions. Notably, they resolve a previously open question by showing entanglement only appears below a fixed temperature that doesn't depend on how big the system is, even when every particle can interact with every other particle. They also provide a fast, practical classical algorithm for simulating these systems up to just before the quantum transition, useful for benchmarking quantum simulators.

Technical view

The paper establishes sharp, system-size-independent inverse-temperature thresholds for quantum Gibbs states of long-range Pauli Hamiltonians (bounded per-site interaction strength) at which classical-mimicking properties (unentanglement, zero magic, partition-function analyticity, correlation decay, algorithmic tractability) each individually fail, forming a hierarchy of distinct 'classical-to-quantum' transitions rather than a single crossover. They resolve an open problem from Rouzé, França, and Alhambra (STOC'25) by proving entanglement death occurs at constant (size-independent) temperature even under all-to-all long-range coupling. They also give a polynomial-time classical Gibbs-state preparation algorithm valid up to (and asymptotically colder than) the entanglement-death threshold, giving practitioners a concrete tool for classical simulation limits and benchmarking near-term quantum thermal state preparation.

arXiv · hep-latBuildable

Exact chiral symmetry with quantum signal processing

A new quantum recipe simulates 'perfect' particle physics symmetry almost for free.

In lattice simulations of particle physics, there's a long-standing tension: some ways of representing fermions (matter particles like quarks) on a computational grid break an important symmetry called chiral symmetry, while the versions that preserve it exactly (like overlap fermions) are usually expensive to compute. This paper develops a quantum computing technique — quantum signal processing, a way of precisely sculpting quantum operations — that simulates the expensive, symmetry-preserving version at almost the same cost as the cheaper, symmetry-breaking one. Surprisingly, the method reveals a deep physics connection: the extra 'trick' needed to get perfect symmetry mirrors how these particles emerge from a hidden extra dimension in a related theoretical construction. It matters because it could make quantum simulations of fundamental particle physics both more accurate and more efficient.

Technical view

The authors construct a QSP-based quantum algorithm implementing the overlap fermion Hamiltonian that satisfies the Ginsparg-Wilson relation up to a tunable error ε_e, at a cost only logarithmically larger in ε_e than simulating the Wilson-Dirac Hamiltonian, and with reduced qubit overhead compared to domain-wall fermion simulations (at a modest circuit-complexity cost). They show the QSP construction effectively synthesizes an emergent extra dimension, mirroring the domain-wall origin of overlap fermions as a boundary theory. This gives lattice QCD practitioners a near-optimal, chirally-exact quantum simulation primitive that could be integrated into larger quantum algorithms for lattice gauge theory.

arXiv · quant-phConceptual

Spectral gaps of ironed two-qubit gadgets matching the iSWAP gap

Two different quantum-computer 'shuffle' operations turn out to mix qubits equally well.

Quantum computers often use two-qubit 'gates' (basic operations) applied repeatedly across many qubits to scramble quantum information — this is important for randomness generation and testing quantum chaos. One well-studied gate is called iSWAP; this paper studies a broader family of gates ('ironed two-qubit gadgets') that share a particular mathematical parameter with iSWAP, and proves that whenever this parameter matches, the scrambling speed (measured by a 'spectral gap', essentially how fast the operation mixes things up) is identical to iSWAP's — at least for reasonably large qubit systems. The key mathematical trick uses group theory (symmetry analysis) to pin down exactly where the slowest-mixing part of the system lives. This settles a previously open mathematical conjecture and gives circuit designers more flexibility in choosing gates that achieve the same performance guarantees.

Technical view

The paper proves that any 'ironed' two-qubit gadget with KAK decomposition parameter a=5/9 achieves the same second-moment spectral gap as the iSWAP gadget when applied across all pairs in K_n for n≥5. The proof uses a representation-theoretic localization argument showing the operator's most negative eigenvalue always resides in the highest-spin SU(2) irreducible summand, combined with a local positive-semidefinite decomposition that handles all spin sectors except the top two. This settles a conjecture of Kong, Li, and Liu and gives circuit designers a provable equivalence class of gates for constructing efficient unitary/state 2-designs.

arXiv · hep-phConceptual

Dynamical flattening of halo density cusps by Q-ball dark matter

Exotic dark matter blobs might smooth out the dense cores predicted at galaxy centers.

Standard cold dark matter theory predicts galaxies should have dense, sharply peaked cores at their centers, but real observed galaxies often have flatter, less dense centers — a longstanding puzzle called the 'cusp-core problem.' This paper proposes that dark matter isn't just simple scattered particles but can clump into 'Q-balls' — stable blob-like lumps held together by a conserved internal property, kind of like solitons or persistent wave packets that don't dissipate. Using a representative model, the authors show these Q-balls would grow larger in the crowded, dense centers of galactic halos, and their interactions there naturally flatten out the predicted density spike into something more like what's actually observed. This offers a physically motivated mechanism — rooted in early-universe dark sector physics — for explaining both the cusp-core problem and the puzzling diversity of galaxy rotation curves.

Technical view

The paper models dark matter as non-topological solitons (Q-balls, field configurations stabilized by a conserved global charge) formed in the early universe, and shows that interactions among these Q-balls cause them to preferentially grow in the high-density central regions of dark matter halos. This growth dynamically redistributes central mass, flattening the cuspy NFW-like density profile predicted by collisionless cold dark matter into a cored profile, while naturally producing halo-to-halo diversity in inner density/rotation-curve shape at fixed halo mass. The toy model provides a concrete, simulate-able framework (via Q-ball interaction and growth dynamics) for practitioners to test against rotation-curve data and constrain the dark-sector charge/self-interaction parameters.

arXiv · quant-phConceptual

Spacetime Layout and Logical Compilation of Color Code

Turning abstract quantum programs into precise 3D blueprints for color-code error-corrected computers.

Fault-tolerant quantum computers protect fragile qubits using error-correcting codes, and 'color codes' are a powerful but geometrically tricky scheme for doing this. This paper builds a systematic translation process — a 'compiler' — that converts an abstract description of a quantum computation (drawn as ZX-diagrams, a graphical shorthand for quantum circuits) into a valid 3D layout of color-code patches arranged over space and time, like compiling source code into hardware instructions. It works out the precise geometric rules for how these patches can be legally assembled. This matters because without such compilers, color codes' theoretical efficiency advantages can't actually be turned into working hardware programs.

Technical view

The authors define a spacetime block-diagram representation of color-code logical patches and operations, grounded in the code's anyon-condensation and domain-wall structure, and derive rules governing valid block assembly. They establish a correspondence between this representation and ZX-calculus diagrams, enabling diagram rewrites that preserve the computed logical operation, and build a compilation algorithm that converts arbitrary ZX representations into valid color-code spacetime layouts. This provides a color-code analogue to lattice-surgery compilers used for surface codes, exploiting color codes' richer transversal gate set, and gives a concrete formal target for anyone building color-code-based fault-tolerant compilers.

arXiv · astro-ph.COConceptual

Beyond monomial $α$-attractors

Adding one extra term to an inflation model lets it match surprising new cosmic data.

Cosmic inflation is the idea that the universe expanded incredibly fast right after the Big Bang, and different mathematical models of it predict slightly different patterns in the cosmic microwave background, the leftover glow from that era. Recent data hint the universe's structure varies across scales (the 'spectral index') more than a popular inflation model family called α-attractors usually predicts, unless you crank the model's shape to extreme, oddly-tuned settings. Instead of that single-term ('monomial') tuning trick, the authors try adding a second, natural term to the model's energy function — a mix of quadratic and quartic pieces — and check what it predicts. They find this richer model comfortably reaches the higher values seen in the data through a genuinely different mechanism, which matters because it offers a more natural, less fine-tuned way to explain what the early universe was doing.

Technical view

Monomial α-attractor T-model potentials fit new ns constraints (small-scale CMB plus DESI) only for hyperbolic-tangent power p≥6, requiring the supergravity construction to assume lower-order terms stay negligible throughout inflation and reheating. The authors instead study a binomial potential (quadratic plus quartic term) with quartic coefficient c satisfying 0<c+1/2≪1, finding non-universal ns behavior reaching values up to 0.965 with α-dependence qualitatively distinct from the monomial case. This is presented as a first step toward more general, non-monomial supergravity embeddings of α-attractors, opening testable deviations from standard predictions for future CMB and large-scale-structure analyses.

arXiv · quant-phRunnable

Structure-Preserving Quantum Simulation of Wave Equations on a Trapped-Ion Processor

A real ion-trap quantum computer simulated sound and particle waves on grids up to 4096 points.

Simulating how waves move — sound waves, or the quantum waves of particles described by the Dirac equation — gets very expensive for classical computers as the grid gets bigger, but quantum computers naturally store wave-like states and could do it more efficiently. The researchers designed special quantum circuits, built around the Fourier transform (a way of breaking a wave into its component frequencies), that carefully preserve the wave equations' mathematical structure, then ran them on Quantinuum's H2-2 trapped-ion quantum computer, a real physical machine using charged atoms as qubits. Rather than trying to read out the entire simulated wave, which is expensive, they cleverly extracted just the energy contained in small regions from their measurements. The results tracked the correct classical answer closely across 1D grids of over a thousand points and 2D grids, showing real quantum hardware can now handle noticeably bigger, more meaningful wave simulations than before.

Technical view

They implement structure-preserving, Fourier-based quantum circuits encoding 1D (up to 1024 grid points) and 2D (32×32) acoustic wave dynamics and variable-mass Dirac dynamics, executed on the Quantinuum H2-2 trapped-ion processor with encoded state-space dimension up to 4096. Instead of full-state tomography, they estimate subdomain kinetic energies directly from measurement samples, sidestepping the exponential cost of full readout. Results track classical kinetic-energy dynamics with low mean absolute error across all tested cases, demonstrating a scalable observable-extraction strategy that others could reuse for larger grids or other PDE classes on near-term quantum hardware.

arXiv · quant-phBuildable

Generating broadband optical squeezing via Cascaded Micro-Ring Resonators

Chaining five tiny optical rings creates a wide, flat band of quantum-squeezed light.

'Squeezed light' is a special quantum state where noise in one property is pushed below the normal quantum limit, useful for ultra-precise measurements and quantum technologies, but a single optical cavity can only squeeze light strongly over a narrow range of colors — you normally have to trade squeezing strength for bandwidth. The authors propose chaining several microscopic ring-shaped optical resonators together on a chip, all linked to a shared waveguide, so their combined output produces strong squeezing spread evenly across a wide, flat range of frequencies. They show the design still works well even with manufacturing defects or a broken ring, and remarkably only five rings are enough to closely approximate an idealized 'instant-response' quantum reservoir. This matters because it offers a practical, chip-scale path to more powerful and robust quantum light sources.

Technical view

The scheme cascades N parametric microring resonators coupled to a common bus waveguide to synthesize a broadband, flat-topped squeezed-vacuum spectrum, overcoming the depth-versus-bandwidth trade-off of single-cavity OPO sources. The authors derive the conditions producing a flat-topped spectrum even under realistic intracavity pump attenuation, and show robustness to inhomogeneous resonator detunings and individual component failure. Notably, as few as N=5 coupled rings converge to the ideal Markovian-reservoir limit substantially faster than a single-cavity Lorentzian source, suggesting a near-term integrated-photonics route to broadband squeezed reservoirs for enhanced light-matter coupling.

arXiv · hep-thRunnable

Hayden--Preskill recovery at finite temperature on a quantum processor: dynamics and initial state from the SYK model

Simulated black-hole information recovery still works at realistic finite temperatures, just weaker.

The Hayden-Preskill thought experiment asks: if you drop a bit of information into a black hole that's been scrambling things for a while, can you recover it by collecting its radiation plus an old copy of the black hole? Physicists simulate this scrambling behavior with chaotic quantum circuits (using the SYK model, a toy model of quantum gravity). Here, the researchers link the scrambling process and the starting state together using a SWAP gate, and crucially run the experiment at finite, nonzero temperature — closer to how real black holes behave — rather than the usual idealized infinite-temperature case. They find the information can still be recovered reliably, but recovery gets weaker at lower temperatures because there's less quantum entanglement available to exploit, confirming that strong scrambling is essential. This matters as a controlled probe of the deep link between black holes, quantum chaos, and information, testable on today's quantum hardware.

Technical view

They implement a modified Hayden-Preskill protocol on a quantum processor in which the post-injection scrambler is dynamically related to the initial state via a SWAP gate, generalized to finite-temperature initial states derived from the SYK model. Both postselection probability and conditional recovery fidelity are measured and found to scale proportionally with temperature, consistent with reduced entanglement in the initial state at lower temperature limiting scrambling-based recovery. Late-time analytic estimates derived under a uniform-operator-spreading assumption match the numerics well, giving a quantitative link between scrambling strength and recovery fidelity that could be extended to other finite-temperature chaotic systems or hardware platforms.

arXiv · quant-phBuildable

Optical linewidth narrowing for device-coupled single T centers

Extra laser light calms wandering charges, sharpening a silicon quantum defect's color by 70%.

T centers are atom-scale defects in silicon whose emitted light is tied to a spin, a quantum property that can store information, making them promising building blocks for a future quantum internet. Their big problem is that nearby charges randomly shift around, blurring the color of the emitted light — a phenomenon called spectral diffusion that makes their optical linewidth 100 times broader than it should be, hurting how reliably distant devices can be linked. The researchers shine an extra laser beam, energetic enough to generate free charge carriers, at silicon chips containing single T centers, and those carriers fill up nearby 'charge traps' that would otherwise cause the drifting, stabilizing the local environment. This shrinks the blur by up to 70%, and they build a mathematical model explaining exactly how and why it works. Sharper color lines directly improve how well these devices could be linked together for quantum networking.

Technical view

Using above-band excitation delivered via a laser scanning microscope on device-coupled single T centers in silicon, the authors demonstrate up to 70% reduction in optical linewidth, attributed to photo-generated free carriers filling nearby charge traps and suppressing spectral diffusion. They probe charge stabilization dynamics with pulsed above-band excitation and fit a rate-equation model that reproduces both the linewidth narrowing and an accompanying spectral shift. This gives an all-optical, fabrication-free protocol that device engineers can apply to push T-center emission closer to its cavity-limited radiative linewidth, a prerequisite for high-fidelity photon-mediated entanglement in quantum network nodes.

arXiv · quant-phBuildable

Mitigating quantum decoherence via global optimal control

Shaped global control pulses protect a shared-drive quantum chip from noise, not just single qubits.

Some proposed quantum computer designs drive all their qubits with a single shared control signal rather than addressing each one individually, which is simpler to build but makes it much harder to shield any one qubit from noise since you can't isolate it. The researchers study a specific ladder-shaped arrangement of superconducting qubits and use 'optimal control' — carefully reshaping that single global signal — to fight decoherence, the gradual loss of quantum information to energy loss and random phase noise from the environment. Using a simulation technique called tensor networks, which efficiently represents large quantum systems, they show a smarter pulse shape can perform the same operations roughly ten times faster, sharply limiting how much noise can degrade the result. This matters because it shows that appealingly simple, globally-driven quantum hardware doesn't have to sacrifice robustness to noise.

Technical view

Using tensor-network simulation of a globally-driven quasi-2D superconducting ladder architecture, the authors quantify how amplitude-damping and dephasing degrade information flow and one-/two-qubit gate fidelities under global drives. They apply optimal control to reshape the global pulse, compressing gate-sequence duration by roughly an order of magnitude and restoring high fidelities despite decoherence acting on every physical qubit, including ancillas outside the logical register that sustain the ordered phase. This shows decoherence mitigation in globally-driven processors must target the whole drive protocol rather than isolated qubits, offering a template optimization approach for other global-control hardware proposals.

arXiv · cond-mat.str-elRunnable

From Exact Diagonalization to DMRG: A Complete Numerical Study of the Transverse-Field Ising Model

A meticulous numerical rebuild of a classic quantum spin-chain model exposes and fixes a subtle bug.

The transverse-field Ising model is one of physics' simplest yet richest toy systems — a chain of quantum spins that flip under a magnetic field, famous for undergoing an exactly solvable quantum phase transition. This study computes its properties two ways: exact diagonalization, which directly solves the full quantum equations but only works for small chains (up to 20 spins), and DMRG, a cleverer approximate method that compresses the quantum state and scales up to 100 spins. Using identical settings and checks at every system size, the authors pinpoint exactly where a previous, less careful analysis produced a spurious glitch from insufficient numerical precision, and fix it. This matters as a trustworthy reference and cautionary tutorial for anyone learning to simulate quantum many-body systems, since plausible-looking numerics can quietly be wrong.

Technical view

The authors benchmark exact diagonalization (L=8,14,20) against DMRG (up to L=100) for the 1D transverse-field Ising model using one consistent field grid and convergence diagnostic — independent runs at bond dimensions χ=100 and 200 at every point — verifying exact agreement where the two methods must coincide. They identify and correct a bond-dimension convergence artifact that had produced a spurious discontinuity in an earlier, less systematic dataset, documenting it as a worked example of a common DMRG pitfall. From the corrected dataset they extract the critical point's central charge via two complementary methods, providing a validated, reproducible pipeline and diagnostic checklist for entanglement-based DMRG studies of critical spin chains.

arXiv · math-phConceptual

Integrability in Asymptotic Symmetries of Spacetime: the $\text{BMS}_3$ scenario

Physicists find hidden mathematical machinery that makes flat-spacetime symmetries behave like a solvable puzzle.

When physicists study gravity near the 'edge' of spacetime (like the boundary of a flat, empty universe far from any matter), they find a special set of symmetries called BMS symmetries that describe how that edge can be reshaped. This paper revisits earlier work showing that these symmetries have an 'integrable' structure, meaning a mathematically ideal case where you can solve the equations exactly and systematically, layer by layer, similar to how a puzzle with clear rules is easier to solve than a chaotic one. The authors use different, more structural mathematical tools to reconfirm and extend this result, including checking that a related version for curved (anti-de Sitter) spacetimes reduces correctly to the flat case, and showing there may be more than one way to build this solvable structure. Why care: this kind of exact solvability offers a rare foothold for understanding gravity's behavior at spacetime's boundary, which is central to modern ideas like holography and black hole information.

Technical view

The paper re-derives and generalizes the bms3-integrable hierarchy of Fuentealba et al. (2018) by constructing a bi-Hamiltonian structure via the variational complex on the ring of polynomial symbols, onto which a Nijenhuis operator (a recursion operator ensuring compatibility of Poisson structures) is attached, establishing integrability in the classical sense. An analogous construction is carried out for AdS3, with an explicit flat-limit check recovering the bms3 result, an alternative tau-function scheme is presented, and a Lie-Poisson analysis shows the hierarchy is not unique. For a subclass of energy-dependent Schrödinger (Lax) operators, the Lax flows are identified with coadjoint orbits of the bms3 algebra, giving a concrete route for readers to construct further conserved charges or explore other admissible bi-Hamiltonian/Nijenhuis structures on asymptotic symmetry algebras.

arXiv · quant-phConceptual

Quantum Steering and Nonlocal Correlations Between Non-Interacting Delocalized Electrons Under Rashba Spin-Orbit Interaction

Two electrons that never touch can still share spooky quantum links, tuned by a spin-twisting effect.

In certain ultra-thin materials, electrons moving around get their spin (a quantum property a bit like a tiny compass needle) twisted just by their motion, an effect called Rashba spin-orbit interaction. This study asks whether two separate, non-interacting electrons in such a material can share quantum entanglement-like connections, specifically 'steering' and 'nonlocality', where measuring one electron instantly tells you something about the other, even though they aren't directly interacting. Using a real material (a bismuth layer on silver) known for strong Rashba effects, the researchers mathematically dialed the strength of this spin-twisting and the distance between electrons to see how these quantum connections change. Surprisingly, cranking up the effect first weakens the quantum links but then, at a specific 'sweet spot' strength, the links bounce back stronger, showing this spin-orbit knob can be used to control and preserve fragile quantum properties, which matters for building quantum technologies out of solid materials rather than isolated particles.

Technical view

The authors compute quantum steering, Bell nonlocality, and uncertainty-induced nonlocality between two non-interacting electrons in a 2DEG as functions of Rashba spin-orbit interaction (RSOI) strength α_R and inter-electron separation, using the Bi/Ag(111) system (α_0 = 3.05e-11 eV·m) as a concrete benchmark. All three correlation measures show non-monotonic behavior with α_R: initial suppression followed by a recovery peak near α_R ≈ 4.32e-11 eV·m, robust across the separations studied. This identifies RSOI strength as a tunable control parameter for engineering and stabilizing nonclassical correlations in solid-state 2DEG platforms, offering a concrete target coupling regime for experimentalists designing spin-orbit-coupled qubit or sensing schemes.

arXiv · gr-qcConceptual

Dynamics of compact binary systems in massive scalar Gauss-Bonnet gravity

Physicists calculate how two black holes would spiral together if gravity carries a hidden massive field.

Einstein's general relativity is our best theory of gravity, but physicists test it by considering modified versions, one candidate adds a 'scalar field' (an extra invisible field coupled to spacetime curvature) that could subtly change how gravity behaves, especially in extreme places like near black holes. This paper studies a version of that theory where the extra field also has mass (weight), which changes its behavior over distance, and calculates in detail how two orbiting, non-spinning black holes would move under this theory: their orbital motion, the two objects' combined center-of-mass, and how much energy is bound in the system, for both circular and oval-shaped (eccentric) orbits. They do this using a standard approximation technique (like adding correction terms to Newton's gravity), extending previous work to include, for the first time, the effect of the scalar field's mass together with the curvature coupling. This matters because gravitational-wave detectors could compare real black hole merger signals to these predictions to test whether gravity really has this hidden extra ingredient.

Technical view

The authors work in massive scalar-Gauss-Bonnet (sGB) gravity, where a scalar field couples to the Gauss-Bonnet quadratic curvature invariant and carries an explicit mass term, and derive the post-Newtonian (PN) dynamics of a nonspinning black hole binary up to 1PN order. They obtain the equations of motion, the center-of-mass frame transformation, and the binding energy for both circular and eccentric orbits, incorporating for the first time the combined effects of the scalar mass and the Gauss-Bonnet coupling at this PN order. These results provide analytic templates that can feed into gravitational waveform models (e.g., for LIGO/Virgo/LISA-type searches) to place bounds on the scalar mass and coupling strength via binary inspiral observations.

arXiv · astro-ph.COConceptual

Inflation, Open Universes, and Dark Energy

A tiny curve in the universe's shape could resolve a nagging mismatch in Big Bang theories.

Cosmologists measure a number called the 'spectral index' (n_s), which describes tiny ripples in density left over from the universe's earliest moments (inflation) that seeded all galaxies and structure we see today. Different simple, well-liked models of inflation predict slightly different values of n_s, and there's been a mild tension between what's measured and what the simplest models predict. This paper combines multiple huge datasets, from the cosmic microwave background (the universe's oldest light) and galaxy surveys, and asks what happens if you allow the universe's overall geometry to be slightly curved (rather than perfectly flat) or allow dark energy (the mysterious force pushing the universe apart) to change strength over time, instead of assuming it's constant. They find that adding a small amount of negative curvature, or letting dark energy evolve, nudges the measured n_s value toward what popular inflation models actually predict. This matters because it hints that two separate cosmological puzzles, the shape of inflation and the nature of dark energy, might be connected, and resolving one could resolve the other.

Technical view

Using a joint dataset spanning Planck, SPT, and ACT CMB measurements plus DESI BAO and full-shape galaxy clustering, the authors fit models allowing nonzero spatial curvature (Ω_k) and a dynamical dark energy equation of state (w0, wa) and examine the resulting shifts in the inferred spectral index n_s. They report Ωk ≈ 3×10^-3 lowers n_s toward values favored by Starobinsky, Higgs, and simplest α-attractor inflation models, yielding n_s = 0.9667±0.0041 (Planck+DESI) or 0.9692±0.0035 (adding ACT/SPT); allowing time-varying dark energy similarly shifts n_s to 0.9716±0.0032 (combined) or 0.9694±0.0035 with curvature included. The result suggests degeneracies between curvature, dark energy dynamics, and n_s that practitioners modeling inflation or dark energy should account for jointly rather than fixing Ωk=0 and w=-1 by default when comparing to inflationary predictions.

arXiv · astro-ph.HEConceptual

Binary neutron stars in the next-generation era: Multi-messenger detection prospects and constraints on the equation of state, mass distribution, and cosmology

Future gravitational-wave detectors could catch up to 100 neutron-star collisions a year, lit up in light too.

When two neutron stars (the ultra-dense remnants of dead stars) collide, they send out ripples in spacetime called gravitational waves, and also a burst of light and other radiation, a 'multi-messenger' event, like the famous 2017 detection. This paper looks ahead to next-generation gravitational-wave observatories (Einstein Telescope and Cosmic Explorer), which will be far more sensitive than today's detectors, and estimates how many of these combined gravitational-wave-plus-light detections we could expect per year, and how well they could measure the internal makeup of neutron stars, the range of neutron star masses, and even the universe's expansion rate. Using statistical modeling techniques and assumptions about how often these collisions happen and how heavy neutron stars typically are, they predict that the Einstein Telescope alone could yield roughly 40 to 100 successfully identified light-based counterparts per year. Why it matters: more of these paired detections would sharpen our understanding of exotic nuclear matter and give an independent way to measure how fast the universe is expanding, addressing an active controversy in cosmology.

Technical view

The authors forecast multi-messenger binary neutron star (BNS) detection rates for the Einstein Telescope (ET) and Cosmic Explorer (CE), and propagate these through joint hierarchical Bayesian inference to project constraints on the neutron star equation of state (EOS), BNS mass distribution, and cosmological parameters (e.g., H0). Assuming a local merger rate of 106.6 Gpc^-3 yr^-1 and testing both a narrow mass function centered at 1.4 M_sun and a wide 1.1-2 M_sun function, they find ET alone yields ~40-100 electromagnetic-counterpart-identified events per year depending on detector layout and mass distribution assumptions, with further gains from a joint ET+CE network. This provides a quantitative basis for designing follow-up strategies and prioritizing EOS/cosmology science cases for next-generation GW facility proposals.

arXiv · quant-phBuildable

Classical Tensor Network and Quantum Fourier Transform Approaches for Large-Scale Carr-Madan Option Pricing

A quantum-computing trick, run on ordinary computers, makes pricing millions of stock options far less memory-hungry.

Banks and traders price options (financial contracts whose value depends on a stock's future price) using math that relies on Fourier transforms, a technique for breaking signals into wave-like components, applied to something called the Carr-Madan method. The problem is that as you want finer and more detailed pricing grids, standard Fourier calculations demand exploding amounts of computer memory, becoming a bottleneck for large, realistic pricing problems. This paper borrows an idea inspired by quantum computing, the Quantum Fourier Transform, but implements a compressed, classical version of it using 'tensor networks' (a way of representing huge grids of numbers compactly by factoring them into smaller connected pieces, roughly like efficient origami-folding of data) so that the calculation never has to build the full giant array in memory. They apply this directly to option pricing, avoiding ever constructing the exponentially large data structures a naive approach would need, and compare it against a true quantum computing approach. This matters because it could let financial institutions price options with much finer detail and scale without needing quantum hardware or massive memory.

Technical view

The authors reformulate the Carr-Madan Fourier-based European option pricing framework using tensor networks, specifically applying the Superfast Fourier Transform (SFFT), a Tensor Train (compressed matrix product) representation of the Quantum Fourier Transform, directly to the tensorized pricing computation without ever materializing the exponentially large price/Fourier vectors explicitly. This classical tensor-network algorithm sidesteps the memory bottleneck of standard FFT-based Carr-Madan pricing at fine discretizations, and the paper draws a direct comparison between this classical tensor-network approach and genuine quantum-hardware QFT-based pricing. Practitioners working on large-scale derivatives pricing could adopt the SFFT/Tensor Train formulation as a drop-in replacement for classical FFT pricers to scale to much finer strike/maturity grids on classical hardware.

arXiv · quant-phBuildable

Improved Convergence of Carleman-Embedded Quantum Algorithm for the Vlasov-Poisson System

Quantum algorithms for simulating plasma physics now converge reliably over a wider range of conditions.

Plasma physics (the study of ionized gases, like those in fusion reactors or space) is governed by the Vlasov-Poisson equations, which are notoriously hard to simulate because they track particles' positions and velocities together in a huge space. One promising approach uses quantum computers via a mathematical trick called Carleman embedding, which converts the nonlinear plasma equations into a larger but linear system that quantum algorithms can handle, but earlier versions of this method only worked, or 'converged' to correct answers, under a narrow set of conditions. This paper expands the range of situations where the method reliably works, using both mathematical proofs and numerical tests, by representing the plasma's particle-velocity distribution using a Fourier-Hermite expansion (a way of breaking a complicated shape into simpler wave-like and bell-curve-like building blocks). They find that to make the method converge well as you demand more detail in velocity space, you generally need to add proportionally more particle collisions (friction-like interactions) into the model. This matters because it's a concrete step toward eventually simulating plasmas, relevant to fusion energy and space weather, on quantum computers.

Technical view

The paper extends the proven convergence regime of Carleman-embedded quantum algorithms for the collisional Vlasov-Poisson system, establishing both analytical and numerical lower bounds on convergence for physically realistic collision frequencies, using a Fourier-Hermite expansion of the shifted phase-space distribution function as the basis. They show that for a broad class of basis functions, convergence of the Carleman linearization requires collision frequency to scale up with increasing velocity-space resolution (i.e., finer Hermite truncation demands stronger collisional damping to remain in the convergent regime). They further note the algorithm's computational complexity depends strongly on whether the desired output is time-averaged versus time-resolved, which is directly relevant for practitioners choosing Carleman truncation order and collision modeling when designing near-term quantum plasma simulation algorithms.

MAT

Mathematics

26 new
arXiv · math.APConceptual★ flagship

Harmonic, radial, and shell stability of the weighted Einstein constraints on the sphere at infinity

Proving that solutions to Einstein's equations stay well-behaved out toward infinity.

In Einstein's general relativity, the shape of spacetime must satisfy strict 'constraint' equations, and a deep question is whether you can confine gravitational effects to a region — a kind of 'gravitational shielding.' Controlling how solutions behave far away, out near the sphere at infinity, requires taming certain delicate mathematical operators built from those constraint equations. This paper introduces and proves three notions of stability — harmonic, radial, and shell — that respectively keep borderline modes, radial averages, and coupled radial-angular behavior under control. The technical engine is a set of weighted 'Poincaré' inequalities, classic tools that bound a function by its variation. This is foundational mathematical physics underpinning the authors' companion result on optimally localizing gravity.

Technical view

The paper studies fourth- and second-order differential operators on domains of the sphere in arbitrary dimension arising as weighted compositions of the linearized Einstein constraint operators with their adjoints, central to the authors' resolution of the optimal-localization (gravitational-shielding) problem. It establishes three stability notions — harmonic (borderline harmonic modes), radial (radial evolution of spherical averages), and shell (coupled radial-angular evolution) — controlling asymptotic behavior of constraint solutions near infinity. The main results derive these stabilities from weighted Poincaré-type inequalities on spherical domains. Specialists in mathematical GR can use these coercivity estimates as the analytic backbone for gluing/localization constructions (cf. companion arXiv:2312.17706).

arXiv · quant-phConceptual

Explicit Matrices over $\mathbb Z_2$ with CNOT and Row Complexity $4n-\mathrm{o}(n)$ and Local Logic Gates

Mathematicians build explicit, provably near-worst-case-hard puzzles for reversible 'flip switch' logic circuits.

In reversible and quantum computing, complex operations are often built from simple building blocks like CNOT gates, and a natural question is how many such gates are needed in the worst case to carry out a given transformation. Counting arguments already told researchers that such maximally 'hard' transformations must exist somewhere, but nobody had pointed to a specific, concrete example. Here the authors explicitly construct a family of grid-like binary transformations (matrices of 0s and 1s) that provably need close to the maximum possible number of simple operations — about four times the grid's size — to undo. They show this holds even when the allowed toolkit is expanded to more powerful building blocks, not just CNOTs. Along the way they uncover a precise mathematical link connecting these circuit operations to basic linear algebra. This matters because concrete 'hard' examples are valuable tools for testing circuit compilers and understanding the true limits of circuit complexity.

Technical view

Constructs an explicit family of invertible n×n matrices over Z2 requiring at least 4n − o(n) CNOT/row operations to reduce to the identity, matching known non-constructive counting bounds on generic matrix complexity but with a concrete, verifiable instance rather than an existence proof. Extends the same lower bound to the strictly more powerful model where gates may be arbitrary invertible linear transformations on coordinate pairs ('local logic gates'), not just CNOTs. Proves the permutation group G_n generated by local logic gates on {0,1}^n is naturally isomorphic to the group of invertible affine transformations of Z2^n, reducing questions about permutation complexity in G_n to matrix row-reduction complexity — a structural bridge useful for circuit lower-bound research, compiler benchmarking, and cryptographic linear-layer hardness arguments.

arXiv · math-phConceptual

Redundant moments of non-melonic random tensor models: simplifying the tensor bootstrap

A math shortcut throws out redundant data, making an exotic 'tensor bootstrap' technique far simpler.

In advanced theoretical physics, researchers use 'bootstrap' methods to constrain complicated theories (called tensor models, generalizations of matrix-based quantum theories) using only consistency requirements, without solving them directly — this involves building huge grids of numbers ('moments') and checking they satisfy certain positivity conditions, similar to techniques used in other areas of physics. This paper proves that a large chunk of those numbers, associated with so-called 'melonic' diagrams (a particular pattern of connections named for their shape), are actually redundant — their values are fully determined by just one simple property (their degree), so they don't need to be independently computed. This makes the entire bootstrap calculation dramatically simpler and more tractable, and the trick works broadly across many types of tensor models, not just melonic ones, which should make this powerful but computationally heavy technique more accessible to researchers.

Technical view

The authors prove that in the large-N limit of arbitrary tensor models, any melonic operator's expectation value depends only on its degree, establishing redundancy among the moments that populate the positive semidefinite matrices central to the tensor bootstrap (tensor-model analogues of Toeplitz/Hankel matrix positivity constraints from random matrix and lattice gauge theory bootstraps). They extend this to show an analogous simplification in the Schwinger-Dyson equations governing melonic moments. The result substantially reduces the dimensionality of the bootstrap's semidefinite programming problem and applies beyond purely melonic tensor models, directly simplifying numerical implementations of the tensor bootstrap program.

arXiv · math.COConceptual

On Degree Powers in Intersecting Families

A clever math trick nails down exactly which set of overlapping groups is 'most crowded' at every scale.

Imagine choosing groups of items from a big pool so that every pair of groups shares at least one common item — mathematicians call this an 'intersecting family.' A natural question is which such collection makes certain items appear in the most groups possible, measured in various ways (like summing up how popular each sub-group of items is, raised to some power). This paper develops a new proof technique that approximates these complicated power sums using a simpler quadratic (squared-term) formula, which is much easier to analyze exactly. Using this trick, they prove that the simplest possible intersecting family — one built by just fixing certain items in every group — is always the best choice, and they pin down exactly when other families can tie for best. This kind of result matters in combinatorics because it sharpens our understanding of extremal (best-possible) structures, which show up in coding theory, statistics, and computer science.

Technical view

The paper studies degree-power sums l_{r,p}(F) = sum_R d_F(R)^p over t-intersecting families F in the k-subsets of [n], generalizing classical codegree extremal problems. The core technical contribution is a two-moment interpolation argument that majorizes x^p (for real p>=2) on integer lattice points by a quadratic upper bound, reducing the problem to bounding just the first two falling moments of the degree sequence, which are tractable via combinatorial counting. Combined with Bey's size-sensitive quadratic inequality, they prove the full t-star (fixing a t-subset) maximizes co_p(F) for all real p>=2 in the sharp range n>=(t+1)(k-t+1), extending to all nontrivial degree levels r for intersecting families with n>=2k, and characterize all equality cases. This unifies and extends prior results previously known only for integer p or specific degree levels, giving a reusable interpolation framework applicable to other extremal set theory problems.

arXiv · math.PRConceptual

Tampered Memory Elephant Random Walk on One-Dimensional Integer Lattice

A random walk with 'selective amnesia' reveals how much memory it takes to make history matter.

An 'elephant random walk' is a mathematical model of a walker, like a particle or decision-maker, whose next step depends on remembering some of its past steps — elephants supposedly never forget, hence the name. A big open question is how much memory is actually needed for the walk's long-term behavior to shift between different regimes, like moving slowly and predictably versus wildly and erratically. This paper introduces a 'tampered memory' version where the walker's memory is deliberately split into two parts: on one part it remembers and behaves like the classic elephant walk, and on the other part it 'forgets' and just takes fresh random steps instead. By controlling how these two parts are mixed together over time, the researchers can study exactly where the tipping point for memory-driven behavior lies. This matters because similar memory-dependent processes show up in models of learning, reinforcement, and even biological or financial systems where past experience shapes future action.

Technical view

The authors define a tampered memory elephant random walk on Z, where the memory set at each step n is partitioned into D_n (replaced by independent innovations, i.e. simple random walk steps) and its complement D_n^c (behaving as standard elephant random walk memory). This creates a superposition of two competing stochastic drivers, letting the authors isolate how the size and structure of D_n controls the classical diffusive/critical/superdiffusive phase transition first characterized by Gut and Stadtmuller. Under a renewal-structure assumption on the growth of {D_n} and {D_n^c}, they establish a law of large numbers for the resulting process, laying groundwork for finer scaling-limit results (e.g. CLTs or functional limit theorems) that pin down the exact memory threshold needed to preserve each regime. This gives a concrete, tunable model for testing how much 'forgetting' a self-reinforcing stochastic process can tolerate before losing its anomalous long-range behavior.

arXiv · math.NTConceptual

$\mathbb Q\setminus\mathbb Z$ is diophantine over $\mathbb Q$ with $7$ unknowns

A single polynomial equation with just 7 variables can now detect 'not-a-whole-number' among rationals.

In number theory, a 'diophantine' definition of a set means you can describe membership in that set purely by asking whether a certain polynomial equation has a solution in whole or fractional numbers. In 2016, a mathematician proved that the set of rational numbers that are NOT whole integers can be defined this way, but his equation needed extra helper variables to work, 10 of them in the best prior version. This paper shows you only need 7 extra variables to pull off the same trick, beating that previous best of 10. This might sound abstract, but it's a big deal because these kinds of results connect to Hilbert's Tenth Problem, a century-old question about whether there's a general algorithm to solve polynomial equations, and here fewer variables gives sharper impossibility results, showing certain more complex mathematical questions can never be answered by any algorithm at all.

Technical view

The paper improves the explicit diophantine definition of Q\Z over Q, exhibiting a polynomial P(t,x_1,...,x_7) in Z[t,x_1,...,x_7] such that t is not in Z iff P has a rational root in the x_i, reducing the auxiliary variable count from Daans' 2024 bound of n=10 down to n=7, building on Koenigsmann's original 2016 existence proof, and the result is shown to generalize to arbitrary global fields. Combined with Z.-W. Sun's prior reduction, this yields an explicit undecidability result: there is no algorithm to decide, for F(x_1,...,x_16) in Z[x_1,...,x_16], the truth of a for-all/exists rational sentence with 9 universal and 7 existential quantifiers, tightening the known unsolvability boundary within the arithmetic hierarchy over Q. Practitioners working on Hilbert's Tenth Problem over Q, still open in general, can use this smaller polynomial as a more tractable building block for further undecidability or complexity reductions.

arXiv · cs.GTConceptual

The Complexity of Kemeny Aggregation with Three Rankings

Merging just three ranked lists into one fair compromise is provably intractable.

The Kemeny rule is a way of blending several people's ranked lists (like ballots or search-result rankings) into one 'consensus' ranking that disagrees with the originals as little as possible, counted by how many pairs of items get flipped out of order. You might expect that with only three rankings to merge, finding this best consensus would be easy — but this paper proves it's NP-complete, meaning no efficient algorithm is likely to exist even in this tiny case, and that stays true even when opinions are almost evenly split on every pair of items. The authors show this by cleverly connecting the ranking problem to graph 'max-cut,' a classic hard puzzle about splitting a network into two groups to maximize disagreement across the split. This matters because Kemeny aggregation underlies things like combining search-engine results, voting systems, and merging rankings from different judges or algorithms — knowing exactly where the hardness kicks in tells engineers when to reach for approximations instead of exact answers.

Technical view

The paper proves Kemeny Score is NP-complete for exactly three unweighted rankings, even restricted to profiles where every candidate pair is split 2-to-1 (minimal majority margin), settling the complexity of the smallest nontrivial voter count. On the same instances, Winner, Unique-Winner, and Possible/Necessary-Precedence are shown Θ₂ᵖ-complete, while recognizing a (uniquely) Kemeny-optimal aggregate is coNP-complete — mirroring complexity results previously known only for larger, unbounded voter counts. The reduction is from Max-Cut on tournaments of majority dimension exactly 3, and critically it's tight: the optimal Kemeny score directly yields the exact max-cut value, and any Kemeny-optimal aggregate can be decoded back into a maximum cut. The result generalizes to a sharp dichotomy for every fixed number of voters q≥3 and minimum pairwise support s, giving a full complexity map practitioners can use to identify exactly which aggregation settings admit efficient algorithms versus which require heuristics or ILP solvers.

arXiv · math.AGConceptual

Boundedness of polarized foliated surfaces

A huge zoo of surfaces with hidden flow patterns turns out to sort into finitely many families.

In geometry, a 'foliation' is like a pattern of curves sweeping across a shape, similar to the grain running through a piece of wood or the streamlines in a flowing fluid. Mathematicians have a powerful toolkit, the minimal model program, for taking complicated shapes and simplifying them step by step down to their essential forms; this paper extends that toolkit to surfaces that carry both an ordinary geometric structure and one of these flow patterns. Using the simplified forms, the authors prove a 'boundedness' result: as long as a certain size measurement (volume) doesn't get too large, all such surfaces fall into a finite number of families rather than an endless, unclassifiable variety — much like how, despite endless individual variation, all life sorts into a finite number of species. This kind of classification result is foundational in algebraic geometry because it turns 'there might be infinitely many weird cases' into 'we can actually list and study them all.'

Technical view

The authors establish the minimal model program (MMP) for klt adjoint foliated surfaces and use it to prove that ε-lc adjoint foliated surfaces with nef adjoint canonical divisor and a nef-and-big integral polarization form a bounded family whenever the volume of their sum is bounded above — a foliated analogue of classical boundedness theorems for polarized varieties. As corollaries they get boundedness and effective birationality for general-type adjoint foliated surfaces plus a uniform positive lower bound on their volumes (a Noether-type inequality), and for ε-lc Calabi–Yau adjoint foliated surfaces they show the canonical volumes of rank-one foliations on the underlying surfaces lie in a fixed discrete set — a gap/discreteness theorem. This extends the foliation-MMP program (building on work of McQuillan, Cascini–Spicer, and others) into the boundedness regime pioneered for ordinary varieties by Hacon–McKernan–Xu, giving foliation theorists concrete tools for classification problems.

arXiv · math.PRConceptual

On two differing geometric descriptions of the passage from microscopy to macroscopy in Markov diffusion theory

Two rival mathematical bridges from jittering particles to smooth flowing clouds get connected.

Imagine tracking a swarm of randomly jittering particles (like pollen in water), then zooming out until that swarm looks like a smooth, continuously flowing cloud of density described by an equation (a diffusion or heat-type equation), and then studying quantities computed from that cloud that themselves obey elegant flow-like update rules. This chain — particles, to crowd density, to smooth density, to flow-of-quantities — is a well-known hierarchy in probability and physics, but there are two different rigorous mathematical languages for formalizing the middle jump from 'random particles' to 'smooth flowing shape,' and they don't obviously agree. This paper builds a precise mathematical bridge connecting those two languages, treating the space of all possible smooth probability clouds as itself a kind of infinite-dimensional curved space (a manifold) and carefully sorting out which mathematical objects correctly represent 'directions of change' in that space. This matters because it unifies tools used across statistical mechanics, PDE theory, and modern machine learning methods like diffusion-based generative models, all of which rely on this same particle-to-density passage.

Technical view

The paper constructs a mediating object between two established geometric formalizations of the microscopic-to-macroscopic limit in Markov diffusion theory — likely the stochastic-process/McKean–Vlasov route versus the Otto-calculus/Wasserstein-gradient-flow route on the space of densities. It treats the space of smooth positive probability densities on a closed Riemannian manifold as an infinite-dimensional Fréchet manifold, distinguishing its 'full' continuous cotangent space (arbitrary distributions) from a smoother 'regular' cotangent subspace, and pins down how the choice of continuity-equation operator (mapping particle velocity fields to measure evolution) differentiates the two descriptions. This clarifies the rigorous relationship between particle-level convergence theorems and PDE/variational-calculus-level gradient-flow structures, offering a foundation practitioners in optimal transport, functional inequalities, or diffusion-model theory could build on to move results between the two frameworks.

arXiv · math.COConceptual

From Kreweras walks to branching perimeter processes of percolated triangulations

A random walk from card-shuffling math turns out to secretly trace the edge of a random triangle-tiling.

Picture a shape randomly tiled into triangles, then randomly colored (like a coin flip on each triangle) to create a percolation pattern — this creates wiggly boundary lines between colored regions. There's a technique called 'peeling' for exploring such a random tiling piece by piece along one of these boundaries, and as you peel, the length of the exposed edge (the perimeter) bounces around randomly. This paper shows that this bouncing perimeter is, in an exact geometric sense, the same thing as a well-studied kind of random walk called a Kreweras walk (originally from combinatorics, related to card-shuffling-style counting problems), and that this correspondence still holds when the exploration is allowed to branch into a tree of simultaneous explorations. The payoff is a cleaner explanation for why certain advanced continuum models used to describe the limiting shapes of huge random surfaces (built from something called growth-fragmentation processes) are secretly related to families of correlated random zig-zag paths (Brownian excursions) — tightening the links between combinatorics and probability theory of random geometry.

Technical view

Building on a result of Bernardi–Holden–Sun linking percolation-decorated random triangulations to peeling exploration, the authors give an explicit geometric bijection/correspondence between the perimeter process of the peeling exploration along the percolation interface and Kreweras walks (a classical two-dimensional lattice walk model with a small fixed step set). They extend this correspondence to the branching peeling exploration, i.e., a tree-indexed family of simultaneous peelings. The result explains, at a concrete combinatorial level, the previously discovered relationship (Da Silva–Powell–Watson) between growth-fragmentation processes — used to encode scaling limits like Brownian disks — and families of correlated Brownian excursions, giving researchers a discrete-walk toolkit for deriving or re-deriving continuum scaling-limit properties of random planar maps.

arXiv · math.NTConceptual

Sumsets and generalized arithmetic progressions in multiplicative subgroups

Multiplying works cleanly in these number systems, but adding almost never simplifies.

Take a finite number system (like clock arithmetic, but built from prime powers) and look at a subgroup of elements closed under multiplication. The question is whether this set also has a simple additive shape, like an evenly-spaced arithmetic progression. The researchers prove that except for tiny cases (size 1, 2, or 4), these multiplicative subgroups are never simple additive patterns — and for many of them, the set can't even be split into two smaller pieces that add together to form it. This matters because clashes between multiplicative and additive structure are central to additive combinatorics, with uses in cryptography, coding theory, and pseudorandomness.

Technical view

In F_q^× with A a multiplicative subgroup generating F_q over F_p, the paper proves a proper A is a generalized arithmetic progression (GAP) iff |A| ∈ {1,2,4}, and characterizes when the full group is a GAP. It further shows additive irreducibility for families where |A|>4 and p^e ≡ -1 (mod |A|): such A admits no nontrivial sumset decomposition. A companion bound shows any nonzero c has fewer than |A|/2 representations as a sum/difference of two A-elements when the subgroup index ≥3 and |A|≥5. Results feed directly into exponential sum estimates and pseudorandom constructions over finite fields.

arXiv · math.APConceptual

Shallow water models for the dynamics of oscillating water columns

Math models predict how a wave-power device's trapped air pocket 'breathes' with the sea.

An oscillating water column is a wave-energy device where incoming waves push water into a chamber, compressing trapped air like a piston that can spin a turbine. This paper writes down the equations for that motion in shallow water (where the sea is much shallower than the wave length), treating the squeezed air as a spring pushing back on the water. Because the structure and chamber physically constrain the water's movement, the usual wave equations need reformulating, and the authors show the resulting constrained system has well-behaved, predictable solutions. They also try a simpler version where the water inside the chamber is treated as a solid, rigid block. This kind of modeling lets engineers predict a wave-energy converter's performance without costly physical prototypes.

Technical view

Models an OWC via 1D nonlinear shallow water equations or Boussinesq-Abbott equations, coupling fluid motion to chamber air pressure acting as a spring force, with the partially-immersed structure imposing kinematic constraints. Reformulates the constrained system as a transmission problem between the open-water and chamber domains and proves local well-posedness under conservation of total fluid-elastic energy (no structural damping). Also develops a reduced model treating the chamber's upper fluid layer as rigid. Provides a rigorous PDE foundation for numerical simulation and control design of OWC wave-energy converters.

arXiv · math.OCBuildable

Beyond Hand-Derived Inequalities: Decision Diagrams for Cut Generation in Binary Polynomial Optimization

Instead of hand-crafted math tricks, an algorithm now discovers the sharpest optimization shortcuts itself.

Binary polynomial optimization means choosing yes/no variables to optimize a complex objective — a very general, hard problem type behind scheduling, logistics, and more. Solvers speed this up using 'cutting planes,' extra inequalities that trim away bad solutions, which mathematicians have traditionally derived by hand for specific patterns. This paper instead builds a 'decision diagram' — a compact structure encoding many cases at once — that automatically finds the strongest valid cut for any chosen pattern, essentially automating insight that used to require human cleverness. The approach also reveals new solvable problem classes and formal guarantees, potentially making solvers for these hard combinatorial problems more powerful and general.

Technical view

For binary polynomial optimization over a hypergraph's multilinear set, the paper proposes decision-diagram (DD) based cut separation: for a chosen support pattern, a compact recursive DD encoding (representing only vertex variables, with hyperedge variables implicit in the state) separates a facet-defining cut in the local multilinear polytope and lifts it to the original problem. This yields an extended formulation of the multilinear polytope, a width characterization via valid antichains identifying a new polynomially-solvable hypergraph class, and a generalization of classical hand-derived inequalities (two-links, flowers, odd β-cycles). It's directly implementable as a cut-generation subroutine inside branch-and-cut solvers for 0/1 polynomial optimization.

arXiv · math.NTConceptual

Schwartz spaces on L-monoids: non-Archimedean

A decades-long program linking number theory's deepest symmetries is now essentially complete.

Advanced number theory studies how abstract symmetry groups (Galois groups, tied to solving polynomial equations) show up as matrices or transformations called representations. The Langlands program is a vast web of conjectures connecting these representations to other mathematical objects, and one strategy for proving key identities within that web (the Braverman-Kazhdan-Ngô program) involves building special function spaces on certain algebraic structures. This paper finishes that construction for 'non-Archimedean' number systems (which measure closeness differently than ordinary distance), assuming some standard conjectures, and proves it fully with no extra assumptions for matrix groups (GL_n). It closes off a well-known technical gap that specialists in this area have been working toward for years.

Technical view

Completes the Braverman-Kazhdan-Ngô program for Schwartz spaces on L-monoids over non-Archimedean local fields, conditional on the local Langlands correspondence for tempered representations plus a mild assumption on γ-factors of non-supercuspidal discrete series; unconditional for general linear groups. This delivers the desired Schwartz space/Fourier transform framework underlying functional equations for automorphic L-functions in this local setting. Relevant to specialists in the analytic/geometric side of the Langlands program, particularly those working with L-monoids, Vinberg monoids, or BKN-style harmonic analysis.

arXiv · math.NTConceptual

Deformation of the absolute Galois groups of number fields

A bigger algebraic object that contains a number field's entire symmetry group as one piece.

Every number field (like the rationals, or extensions built from them) has an 'absolute Galois group' encoding all the symmetries of its polynomial solutions — one of the most fundamental and mysterious objects in number theory. This paper builds a larger structure, a 'profinite monoid,' that contains the Galois group as its invertible elements, while special non-invertible ('idempotent') elements correspond neatly to sets of prime numbers. The construction also links to other known objects, like the Deligne-Ribet monoid and Witt vectors (an algebraic tool for constructing number systems). It's foundational, purely theoretical work aiming to unify several previously separate structures in arithmetic under one umbrella.

Technical view

Constructs profinite monoids DG_K for number fields K whose unit group is G_K, whose maximal abelian quotient recovers the Deligne-Ribet monoid DR_K, whose idempotents biject with subsets P_K of primes, and whose maximal closed subgroups at idempotents realize exactly the ramification-restricted Galois groups G_{K,S} (with a converse: all such subgroups arise this way). Relates DG_K to Borger-de Smit's p-typical Witt vector formalism, describing the fundamental monoid of the semi-Galois category of Λ-rings via fields of norms of local fields K_p. Offers a unifying monoid-theoretic framework linking class field theory, ramification theory, and Witt vector constructions for arithmetic geometers.

arXiv · math.APConceptual

On boundary regularity for the fractional p-Laplacian with unbounded reactions

Even with rough forcing, solutions to this 'action-at-a-distance' equation stay smooth near the edges.

Some physical and probabilistic processes — like random walks that can jump far in one step — are modeled by 'nonlocal' equations, where a point's behavior depends on influence from far away, not just its neighbors; the fractional p-Laplacian is one such operator. This paper studies solutions inside a bounded region where the forcing (like a heat source) is allowed to be fairly rough or unbounded, and asks how smooth the solution stays right up to the boundary. They prove precise smoothness guarantees (Hölder continuity, meaning no sudden jumps) that depend on how rough the forcing is, and show these results are nearly the best possible. This extends earlier results known for the simpler linear version of the equation to this more general nonlinear, nonlocal setting.

Technical view

For the s-fractional p-Laplacian with homogeneous nonlocal Dirichlet conditions and reaction f ∈ L^q(Ω), the paper proves solutions u are α-Hölder continuous up to ∂Ω, with α below p'(s − N/(pq)) when N/(ps) < q ≤ N/s, and α = s when q > N/s; in the latter regime, u/d_Ω^s extends Hölder-continuously to the closure. The bounds are shown to be nearly optimal and generalize the known linear-case (p=2) boundary regularity theory to the nonlinear fractional p-Laplacian. Relevant to researchers in nonlocal PDE regularity theory and related free-boundary problems.

arXiv · math.NTConceptual

Vertex volumes, lattice-minima tails, and height zeta functions for the standard arithmetic quotient of $\operatorname{PGL}_d$

Measuring the exact 'shape' of an infinite geometric space built from matrix symmetries.

In a field connecting geometry, algebra, and number theory, mathematicians study 'buildings' — highly symmetric infinite structures attached to matrix groups (here PGL_d) that encode arithmetic information, like a map encodes a city's roads. This paper computes the exact 'volume' of pieces of one such building's quotient space using careful symmetry-counting arguments. It then studies a natural height function — a way to measure how large or 'far out' a point is — and pins down precisely how fast its extreme values thin out, plus how a related generating function (a compact formula encoding infinitely many numbers) behaves. This is foundational groundwork useful to anyone doing precise counting or integration on these arithmetic geometric spaces.

Technical view

Studies the nonuniform arithmetic quotient of the Bruhat-Tits building for PGL_d(F_q((t^{-1}))), computing vertex volumes in closed product form via building-theoretic counting (dominant sector parametrization, exact stabilizer counts, cut-set recursion over block compositions). Introduces a homothety-invariant normalized lattice-minima height α, proves α ∈ L^r exactly for 0<r<d, and establishes a sharp cusp-tail estimate of order T^{-d}. Derives convergence of the associated positive-moment height zeta function (the Mellin transform of the cusp-height distribution). Provides exact combinatorial/analytic tools for volume and height computations on Bruhat-Tits building quotients, of use in automorphic forms and arithmetic statistics over function fields.

arXiv · math.MGConceptual

Nearly linear lattice coverings of arbitrary convex bodies

A near-optimal recipe for tiling any convex shape's space with overlapping copies on a grid.

Imagine covering all of space with overlapping copies of some convex shape, placed at the points of a regular grid (a lattice) — how much overlap is unavoidably needed as the number of dimensions grows? This paper proves a far better upper bound than previously known: the required overlap grows only 'nearly linearly' with dimension, times some slowly growing log factors, instead of the roughly squared growth of the best prior bound. Combined with earlier results showing balls can't do better than linear, this pins down the true growth rate for the worst-case shape. The proof uses a clever construction blending probability tools (folded Gaussians) with a combinatorial line-covering result (a finite-field Kakeya theorem) to turn an abstract weighting estimate into an actual geometric covering.

Technical view

Proves lattice covering density θ_L(K) for any n-dimensional convex body K satisfies θ_L(K) ≤ Cn log n (log log n)^{10/3+o(1)}, improving the previous universal O(n²) bound of Ordentlich-Regev-Weiss and matching, up to log factors, the classical linear lower bound of Coxeter-Few-Rogers for Euclidean balls — thus fixing the optimal polynomial growth exponent for worst-case lattice covering density. The construction is a 'vertical-horizontal' method that converts a uniform weight estimate on the Boolean cube into an actual lattice covering for arbitrary K, using folded Gaussians and a finite-field Kakeya theorem in a low-dimensional vertical space to select near-optimal Boolean patterns per translate. The vertical-horizontal technique may generalize to other packing/covering problems in discrete geometry and coding theory.

arXiv · math.NABuildable

Windowed thinning and query complexity for the bouncy particle and Zigzag samplers

A smarter timing trick slashes the number of gradient checks needed to simulate random samplers exactly.

The bouncy particle sampler and Zigzag process are algorithms that draw random samples from complicated probability distributions, a core task in statistics and AI, by simulating a particle that bounces or flips direction randomly over time. Normally you'd need to check constantly whether a bounce/flip should happen, which is expensive; this paper instead splits time into fixed windows and does just one calculation at the start of each window to safely predict what happens inside it. Combining that trick with estimates of how fast the process settles down, the authors prove exact formulas for how many expensive calculations are needed to reach a target accuracy starting from a generic first guess. It matters because it gives concrete, provable efficiency guarantees for these popular exact sampling methods and shows how their cost scales with the size and difficulty of the problem.

Technical view

The authors introduce windowed thinning, which partitions bouncy-particle-sampler and coordinate-Zigzag trajectories into deterministic windows and builds a tractable local envelope for the event rate from a single gradient evaluation per window, avoiding continuous rate checks. Paired with quantitative mixing bounds and finite-time bounds on expected bounce/flip counts, this yields explicit query complexities from a Gaussian cold start: O(κ^{1/2}d(d log κ + log 1/ε)) gradient queries for the bouncy particle sampler and O(κd^{1/4}(d log κ + log 1/ε)) full-gradient equivalents for Zigzag, for m-strongly-convex, L-smooth potentials with condition number κ=L/m. This sharpens the known dimension/condition-number dependence for exact PDMP-based sampling and provides a template (envelope construction + mixing bounds) for analyzing other event-driven MCMC samplers.

arXiv · math.AGConceptual

Stability conditions and moduli spaces on projective families

Mathematicians extend the idea of 'stability' for shapes to whole families of shapes varying together.

In algebraic geometry, researchers classify abstract geometric objects using a notion of 'stability' that sorts them into organized catalogs called moduli spaces. Previously this worked well for one fixed geometric space at a time; here the authors extend the theory so it works when the underlying space itself varies across a family, and prove the resulting catalog stays well-behaved (no missing or runaway pieces). Along the way they confirm a conjectured size bound for these objects, connect the new theory to older notions of stability on surfaces and 3D spaces, and give a simpler proof of a classic theorem about reconstructing a geometric space from more abstract data attached to it. This matters because it unifies and strengthens tools mathematicians use to classify geometric objects across entire families at once, not just isolated examples.

Technical view

The authors extend Bridgeland-type stability conditions from projective schemes over a field to projective families over an arbitrary base and prove existence of proper relative moduli spaces of semistable objects in the derived category. They establish mass-Hom bounds (resolving a conjecture of Halpern-Leistner–Robotis), compare the construction to tilt-stability on surfaces/threefolds, build stability conditions on supported derived categories of total spaces of vector bundles including all local Calabi–Yau varieties, and give a new proof of Bondal–Orlov reconstruction. This is foundational infrastructure likely to underpin future moduli constructions (wall-crossing, DT/PT theory) for families rather than single spaces.

arXiv · math.NTConceptual

Ginzburg's conjecture on the unramified computation of Eulerian integrals

A decades-old conjecture about how a number-theoretic 'integral recipe' factors cleanly finally gets proven.

This work sits in the theory of automorphic forms, a branch of number theory connected to the Langlands program that links number theory, algebra, and analysis. Researchers build special integrals from automorphic objects because, under the right conditions, these integrals split into a product of simple local pieces — one per prime — letting them extract deep number-theoretic invariants called L-functions. This paper proves a conjecture by D. Ginzburg pinning down exactly what that local piece looks like for a specific pairing of representations, and computes an analogous local factor for a related construction using Eisenstein series, a classical tool for building automorphic forms. It matters because nailing down these 'unramified' local computations is a required technical step before such integrals can be used to prove deeper results about L-functions.

Technical view

The paper proves Ginzburg's conjecture computing the unramified local factor of a global Eulerian integral built from a cuspidal automorphic representation of GL_{2r} paired against the generalized Speh representation Δ(τ_2,r) attached to a cuspidal representation τ_2 of GL_2, and performs an analogous unramified computation for an integral involving degenerate Eisenstein series. Such local computations are the technical linchpin of the Rankin–Selberg/doubling method for showing a global integral represents a specific automorphic L-function, so the result likely feeds directly into functoriality or L-function analytic-continuation arguments in that program.

arXiv · math.NTConceptual

Eventually greedy best Egyptian underapproximations of rational numbers via optimal control

Every fraction can be greedily built from unit fractions optimally — an old Erdős puzzle finally solved.

An Egyptian fraction writes a number as a sum of distinct unit fractions like 1/2 + 1/3 + 1/10, an ancient idea mathematicians still probe for surprising depth. Here the authors study 'underapproximations' — sums of unit fractions that get as close as possible to a target from below — and ask whether always grabbing the largest possible next unit fraction, the greedy strategy, eventually becomes truly optimal rather than just decent. They prove this holds for every positive rational number, settling a long-standing question of Erdős and Graham, by reframing it as an optimal control problem, the kind of math engineers use to steer a system toward the best long-run outcome, and analyzing a value function that scores each choice. This matters because it closes a classic open problem in number theory and reveals how fast the denominators in such fraction sums must grow.

Technical view

The authors prove every positive rational admits 'eventually greedy' best Egyptian underapproximations, both allowing repeated denominators and requiring distinct ones, resolving a problem of Erdős–Graham revisited by Nathanson. The technique reformulates greedy-optimality as an optimal control problem for a discrete dynamical system tracking the residual gap, constructs a payoff functional, and analyzes the associated Bellman value function to show eventual agreement between the greedy strategy and the true optimum, yielding asymptotic denominator growth rates as a corollary. They also answer a further Nathanson question by constructing an irrational number whose best Egyptian underapproximation is both unique and greedy at every step.

arXiv · math.AGConceptual

Log Canonical Models and Positive Geometries

Physics-born 'canonical forms' turn out to hand you exact equations for hard geometric spaces.

In algebraic geometry, a central hard problem is taking an incomplete geometric space and filling in its missing boundary in a natural way, then writing down explicit coordinates and equations for the result. Separately, physicists studying how particles scatter developed 'positive geometries' — special shapes paired with a canonical function that encodes the physics. This paper shows that for many spaces, including arrangements of hyperplanes, certain cubic surfaces, and moduli spaces of marked cubic surfaces, those physics-derived canonical functions directly supply the natural coordinates for the completed space, letting the authors write down its defining equations explicitly. It matters because it turns an abstract existence question into something computable and strengthens a surprising bridge between particle-physics math and classical geometry.

Technical view

The authors show that for a large class of open varieties, the log canonical model's compactification admits explicit coordinates given by canonical forms of associated positive geometries (objects originally used to encode scattering-amplitude structure), and use these to compute explicit defining equations. Applications include complements of hyperplane arrangements, cubic surfaces with lines removed, and the moduli space of marked cubic del Pezzo surfaces. This provides a computational bridge between the positive-geometry/amplitudes literature and classical birational geometry (log canonical models, minimal model program), suggesting canonical-form techniques as a general tool for computing explicit equations of compactified moduli and arrangement complements.

arXiv · math.COConceptual

The cycle C9 does not admit uniform mixing

On a 9-node ring, a quantum particle can never spread out perfectly evenly, a computer-aided proof shows.

A continuous-time quantum walk is the quantum version of a random walk: instead of hopping randomly between connected points on a graph, a particle evolves by quantum rules that let it exist in superposition across many points at once. 'Uniform mixing' is the special, useful property where at some moment the particle becomes exactly equally likely to be found anywhere — valuable for quantum search algorithms. This paper proves that on a ring of 9 points, that perfectly even state can never occur, using heavy algebraic machinery called Gröbner basis computation to rule out a special set of numbers that would have been required for it to happen. It matters because it narrows down exactly which small graphs support this useful quantum behavior, guiding which structures are worth using in quantum-walk algorithms.

Technical view

The paper studies continuous-time quantum walks (CTQWs) on cycle graphs C_n, focusing on uniform mixing (the transition matrix reaching uniform magnitude at some time t). Using algebraic geometry and Gröbner basis computations, the authors rule out the existence of 'cyclic 9-roots' satisfying the constraints required for uniform mixing on C_9, proving it does not occur at any time. This resolves a previously open case in the classification of which cycles admit uniform mixing, refining the characterization relevant to quantum-walk-based search and state-transfer algorithm design.

arXiv · math.CAConceptual

Reflected diffusion, no-flux continuity equations and confined Lagrangian flows in bounded domains

Mathematicians pin down exactly when a bouncing fluid-like flow can be traced back to real particle paths.

Picture a substance whose density changes over time inside a sealed container under a 'no-flux' rule — nothing leaks through the walls, like gas bouncing around a box, similar to a 'reflected diffusion,' a random process that bounces off boundaries instead of escaping. The question is whether that evolving density can always be explained by actual particle trajectories that stay inside the box and never cross its wall, a link between a fluid-like description and individual paths called a Lagrangian flow. The authors give precise conditions on how well-behaved the flow must be, especially near the boundary, under which such particle-path explanations are guaranteed, and show these conditions can't be loosened by building an explicit example where particles sneaking along the wall break the correspondence. This matters for the mathematical foundations of physical and probabilistic models with reflecting boundaries, where trajectory-level descriptions are essential for simulation.

Technical view

The authors study when a density/flux pair solving a no-flux continuity equation in a bounded domain admits a regular Lagrangian flow (RLF) confined to the closed domain, motivated by marginal flows of reflected diffusions. They give sufficient conditions — interior BV regularity, BV control in a boundary collar, a one-sided bound on the absolutely continuous divergence, and vanishing normal trace of the velocity — extending Ambrosio–DiPerna–Lions theory to the boundary case by showing tangency removes the singular boundary contribution to the divergence of the zero-extended velocity. They prove these conditions are sharp by constructing an explicit smooth density/flux pair exhibiting a 'boundary current' that obstructs existence of a confined RLF, giving checkable criteria relevant to well-posedness of reflected SDEs and transport equations in bounded domains.

arXiv · math.OCConceptual

Exact and Approximate Solvability of Systems Involving Proximity Operators in Hilbert Spaces

New math tells you exactly when a system of 'nearest-point' rules has a solution, useful for signal recovery.

A proximity operator, or 'prox,' nudges a point to a nearby compromise that balances staying close to the original point with minimizing some function, generalizing the everyday idea of projecting a point onto the closest spot on a shape. This paper asks: given several target compromise points from different functions, when does a single starting point exist whose prox under each function lands exactly on the prescribed target? The authors work out precise conditions for when such an exact solution exists, and separately for when only an approximate one exists, introducing a new 'inverse proximal property' that generalizes an existing idea about inverse best approximation. This matters practically because these systems arise in feasibility problems, finding a point consistent with several constraints, and in signal recovery, reconstructing a clean signal from noisy or partial data, so knowing when a solution is guaranteed helps validate such algorithms.

Technical view

For a finite family of proper, lower semicontinuous, convex functions on a real Hilbert space, the authors characterize existence and uniqueness of exact solutions x to the system prox_{f_i}(x)=p_i for prescribed points p_i, generalizing classical simultaneous-projection problems. They derive necessary and sufficient conditions for approximate solvability and introduce the inverse proximal property (IPP), generalizing the inverse best approximation property (IBAP), with several equivalent characterizations. Applications to convex feasibility problems and signal recovery give practitioners verifiable conditions for when a proximal-based recovery or feasibility algorithm is well-posed and has a computable solution.

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Biology

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arXiv · cs.LGConceptual★ flagship

KAISEN: Reproducible Subgroup Fairness Auditing for Clinical Risk Models

A stress-tested toolkit to check whether medical AI quietly fails some patient groups.

Medical risk-prediction models can look great overall while making far more mistakes for certain groups of patients — say, by income, geography, or disability. People have built 'audit' pipelines to catch this bias, but the auditing tools themselves are rarely tested to see when they break or mislead. KAISEN is a five-stage audit — find subgroups, measure the gaps, diagnose why they happen, try to fix them, and watch for drift over time — deliberately pushed until it fails on a large synthetic testbed of 16 diseases and 15 social-factor dimensions. A key lesson: whether a disparity shows up as 'statistically significant' depends heavily on how big a gap that particular subgroup axis is even capable of detecting, not just on how unfair the model actually is. The point is to tell practitioners which parts of an audit to trust, and under what conditions.

Technical view

KAISEN is a reproducible five-phase fairness-audit pipeline — subgroup stratification, disparity measurement, mechanism diagnostics, post-hoc mitigation, and drift monitoring — evaluated to failure on a synthetic benchmark of 16 disease tasks, 15 social-determinant axes (from Healthy People 2030), and three prespecified intersections. A headline result: significance counts track each axis's gap relative to its own minimum detectable effect, with rank correlation ρ=0.56 between significance count and raw equalized-odds difference (EOD), rising further under stated conditions — i.e., detected 'significance' is confounded by per-axis statistical power. Practitioners can use the framework to distinguish genuine subgroup disparity from artifacts of detectability, and to sanity-check which audit components remain reliable under stress.

arXiv · cs.MAConceptual

Using Theory of Mind to Arbitrate between Social and Non-social Learning

Your brain does cost-benefit math before deciding whether to copy someone or figure it out yourself.

This paper asks a simple question: when do people learn by watching others versus by trying things themselves? The researchers built a model where an agent thinks about what another person is trying to do and how useful watching them would actually be, then compares that against the cost of just exploring on your own. They tested this with a game where players choose to either observe others or explore the environment themselves, and found the model correctly predicted people's real choices. The big idea is that copying others isn't automatic — it's a calculated decision guided by 'Theory of Mind,' our ability to reason about what's going on in someone else's head.

Technical view

The authors formalize a 'Rational Mentalizing' model that computes the expected utility of social learning by inverse-planning over another agent's goals to estimate the informativeness of their likely future actions, then compares this against the utility of independent exploration under a shared cost structure. Validated on a novel game requiring players to choose between observation and exploration, the model quantitatively fits human behavioral trade-offs, outperforming presumably simpler heuristics. This connects Bayesian Theory-of-Mind inference (used elsewhere for goal/intent inference) to the explore-exploit and social-learning literatures, offering a computational account that could be extended to multi-agent or robotic social learning systems.

arXiv · q-bio.QMBuildable

Multi-scale measures of time-varying epidemic spread on human mobility networks

A new math tool tracks how a disease spreads hour-by-hour as people commute, not just city to city.

Epidemiologists usually estimate how fast a disease is spreading using a single number, R(t), that assumes everyone mixes together evenly all day — but real people commute, cluster at work, and disperse at night, which changes how infections actually pass around. This research builds a new mathematical framework that factors in these daily movement patterns between locations, creating several versions of R(t): one for how many infections a place sends out, one for how many it receives, and others for specific commuting routes or meeting spots. The method is built on 'renewal equations,' a standard epidemic-modeling tool, but reworked to plug in real mobility data. This matters because public health responses — like where to focus testing or restrictions — could be much sharper if they account for how people actually move rather than treating populations as uniformly mixed blobs.

Technical view

The paper derives mechanism-led renewal equations on a network-based mobility model, decomposing the classical instantaneous reproduction number R(t) into a family of location- and route-specific indicators: inward and outward R(t) per location, pairwise R(t) between locations, R(t) at shared meeting sites, and an aggregate network-level R(t), all incorporating within-day (not just day-to-day) movement heterogeneity. This generalizes standard homogeneous-mixing renewal-equation estimators (e.g., Cori et al.-style methods) to explicitly encode commuting-driven contact structure. Practitioners with mobility datasets (transit, mobile phone, or census commuting matrices) could use these formulas as drop-in replacements for real-time surveillance to identify which locations or routes are driving transmission, enabling targeted rather than uniform interventions.

bioRxiv · bioinformaticsBuildable

Identifying spatially variable genes by projecting to morphologically relevant curves

Mapping gene activity along the natural curved paths of tissue, not a flat grid.

Spatial transcriptomics is a technology that measures which genes are active at each location across a slice of tissue, like a detailed activity map layered onto a photo. Scientists often want to find genes whose activity changes meaningfully across a specific region, say a strip of tissue like a blood vessel wall or intestinal lining, but that region isn't really flat, it's more like a curved one-dimensional path. Standard methods that just use x-y coordinates miss this natural shape and give messy or misleading results. This paper's approach first mathematically finds the best-fitting curve that traces the tissue's true structure, re-maps every measurement onto that curve, and then uses a flexible statistical model to detect which genes vary meaningfully along it, giving biologists a more accurate way to spot genes tied to a tissue's real anatomical organization.

Technical view

The method addresses spatially variable gene (SVG) detection within tissue regions that are effectively 1D manifolds, such as epithelial layers, where standard 2D coordinate-based SVG methods underperform because they ignore the region's intrinsic geometry. It uses spectral graph theory to extract a principal curve approximating the spatial coordinates of the region, establishing a morphology-aware 1D coordinate system, then fits a GAM (generalized additive model) over this coordinate to detect genes with significant spatial patterns. This provides a more statistically powered and biologically interpretable alternative to 2D spatial smoothing methods for structurally constrained tissue regions. Practitioners working with spatial transcriptomics data, such as Visium or Slide-seq, could adopt this as a preprocessing coordinate-transform step ahead of existing SVG detection pipelines.

bioRxiv · neuroscienceConceptual

RAI1 safeguards fidelity and tempo of human neurodevelopmental gene expression

One gene keeps human brain development from rushing, and losing it may cause autism-linked delays.

Human brains take an unusually long time to develop compared to other animals, and scientists think that slow pace is part of what makes advanced thinking possible. This study looks at a gene called RAI1, which normally helps package and control DNA in developing brain cells, and which is missing a working copy in people with Smith-Magenis Syndrome, a condition involving intellectual disability and autism-like traits. The researchers built stem cell lines missing one or both copies of RAI1 and grew them into brain tissue in a dish, tracking gene activity over time as the cells matured. They found that without enough RAI1, the developmental gene program runs on fast-forward instead of unfolding at its normal careful pace, and single-cell analysis showed how this speed-up plays out across different developing brain cell types. The findings suggest that RAI1's job is essentially to act as a pacesetter, protecting the accuracy and tempo of brain development, and that rushing this timeline may be part of what goes wrong in Smith-Magenis Syndrome.

Technical view

Using isogenic RAI1 heterozygous and homozygous loss-of-function hESC lines differentiated via an in vitro cortical protocol, the authors performed longitudinal bulk transcriptomics and found that RAI1 deficiency accelerates progression through the normal developmental gene expression trajectory. Single-cell RNA-seq further resolved how this temporal acceleration manifests across distinct neural cell populations during differentiation. RAI1 encodes a nucleosome-binding protein, so the phenotype implicates chromatin-level regulation of developmental gene timing, linking RAI1 haploinsufficiency (the cause of Smith-Magenis Syndrome) to disrupted pacing rather than simple loss of gene expression. This isogenic hESC system provides a tractable platform for dissecting how chromatin regulators set neurodevelopmental tempo and could be extended to test other SMS-linked mechanisms or candidate therapeutics that restore normal timing.

bioRxiv · cell biologyBuildable

Live single-molecule imaging reveals global shifts in mRNA mobility during human stem cell differentiation

Scientists filmed individual mRNA molecules moving inside living stem cells as they choose their fate.

Inside a cell, messenger RNA (mRNA) molecules carry instructions from DNA to the machinery that builds proteins, and where those instructions end up inside the cell can matter as much as what they say. This study built a way to tag specific mRNAs in living human stem cells with a glowing marker so researchers could watch individual molecules move in real time under a microscope, using computational tools to classify their movement patterns. They applied this to cells becoming neurons or blood vessel tissue and tracked mRNAs that encode building blocks of the cell's internal skeleton. As cells committed to a final identity, these mRNA molecules consistently shifted from moving freely to being locked into specific zones of the cell, and disrupting the cell's internal scaffolding changed this pattern. This shows that controlling exactly where mRNA sits, not just how much of it exists, is a conserved part of how a cell settles into its identity.

Technical view

The authors developed an MS2-tagging pipeline for endogenous transcripts in human iPSCs, combined with single-particle tracking and Hidden Markov Modelling to classify mRNA diffusive states and construct mobility landscapes during differentiation. Applied to beta-actin and beta2b-tubulin transcripts across neural organoids, directly programmed neurons, and vascular organoids, particle tracking revealed a conserved shift from free diffusion toward constrained, compartmentalized mobility states as cells acquire terminal identity. Cytoskeletal perturbation experiments (implicating microtubule-dependent transport) causally link this mobility shift to the underlying transport machinery rather than passive diffusion changes. The tagging and HMM-based analysis pipeline is generalizable to other endogenous transcripts and cell systems, offering a route to quantitatively map RNA localization dynamics genome-wide during any live cell-state transition.

bioRxiv · cell biologyConceptual

H4K20me3 and CTCF act reciprocally at TAD boundaries to regulate cell state transitions

Two DNA-organizing proteins fight for control at chromosome loop boundaries to flip cells between dividing and resting.

Our DNA is folded into loops inside the nucleus, and the anchor points of these loops help decide which genes turn on or off. This study looks at how cells switch between actively dividing and resting quietly, a switch that happens without the loop anchors themselves moving. The researchers found that two players compete for control at these anchor points: a protein called CTCF that favors active, dividing cells, and a chemical tag on DNA-packaging proteins called H4K20me3 that favors resting cells by physically pushing CTCF out of the way. When they experimentally boosted H4K20me3, cells compacted their DNA, changed the shape of their nucleus, and switched on resting-state genes, and removing the enzyme that makes this tag broke the resting program. In short, a tug-of-war between one protein and one chemical mark, rather than any big rearrangement of the DNA's overall folding, appears to control whether a cell divides or rests.

Technical view

The study identifies a reciprocal antagonism between CTCF occupancy and the histone mark H4K20me3 at TAD (topologically associating domain) boundaries as a mechanism controlling the proliferation-quiescence switch independent of large-scale TAD repositioning. Genome-wide profiling and functional perturbation show elevated H4K20me3 in quiescent fibroblasts displaces CTCF at specific boundaries, driving compact chromatin, altered nuclear morphology, and quiescence-associated transcription, while CTCF binding dominates in proliferating cells and sustains open chromatin and pro-proliferative gene expression even under quiescence cues. Fibroblasts lacking the H4K20me3 methyltransferase KMT5C/Suv4-20h2 show a hyperproliferative phenotype, functionally validating the mark's necessity for the quiescent state. This establishes a boundary-level, mark-versus-factor competition model that practitioners could test at other TAD boundaries or in other cell-state transitions using ChIP-seq/Hi-C plus KMT5C perturbation.

bioRxiv · ecologyConceptual

Host genetics and social relationships jointly shape fitness-associated microbiome variation in a population of feral horses

A horse's genes and its friends both help shape the gut microbes that decide whether it thrives.

Scientists have long known that the trillions of microbes living in an animal's gut can affect its health and survival, but it's been unclear whether this microbiome can actually evolve the way genes do, and whether it's just inherited genetically or also passed along socially, like from a mother or from friends. This study used nearly a decade of data from wild horses living on Sable Island, including genetic records and stool-based microbiome sequencing from almost 800 individually tracked horses, to figure out how much of the variation in gut microbes linked to survival and reproduction comes from genes, from mothers, or from social relationships. They used statistical models borrowed from animal breeding science to tease apart these different sources of inheritance, applied to microbiome traits that were mathematically linked to fitness outcomes. The approach lets them ask, for the first time in one study, both whether these fitness-relevant microbiome traits are heritable and whether natural selection is acting on them. This matters because it suggests an animal's gut community isn't just a personal, one-off trait, but something that can be inherited and evolve across generations through multiple channels at once.

Technical view

Using quantitative genetic 'animal models' applied to shotgun metagenomic data from 2,394 samples across 794 known-fate feral Sable Island horses, the authors partition variance in fitness-associated microbiome dimensions (derived via canonical analysis of principal coordinates) into additive genetic, maternal, and social-transmission components. This is the first study to jointly estimate microbiome heritability and detect natural selection acting on microbiome traits within the same population, while also testing non-genetic inheritance pathways (maternal and social) as contributors to microbiome-mediated fitness variation. The long-term, individual-based pedigree and metagenomic dataset allows disentangling genetic versus environmentally/socially transmitted microbiome effects at a scale rarely available outside model organisms or humans. The animal-model framework applied here is replicable in other wild or captive populations with pedigree and longitudinal metagenomic data to test whether microbiome-mediated adaptation is a general evolutionary phenomenon.

bioRxiv · ecologyConceptual

Macronutrient balance generates distinct nutritional optima for growth, immune function and stress responses in the specialist herbivore Plutella xylostella

Diamondback moth caterpillars need different diets to grow fast, fight infection, or survive stress.

This study looks at diamondback moth caterpillars, a major crop pest, and asks a simple question: does the 'perfect diet' look the same no matter what the body is trying to do? Using a method called the Geometric Framework for Nutrition, researchers fed caterpillars many different mixes of protein and carbohydrate and tracked growth, immune strength, and stress resistance separately. They found that growth mainly needs plenty of protein, but the immune system (measured by immune cells and a defense enzyme) peaked at a middle-ground protein-to-carb ratio, while surviving a bacterial infection depended almost entirely on protein again. In short, there's no single 'best' diet — the ideal balance shifts depending on whether the body is building itself, defending itself, or coping with stress, which matters for understanding animal health and even for designing pest control strategies.

Technical view

Applying the Geometric Framework for Nutrition, the authors mapped Plutella xylostella performance across a protein:carbohydrate (P:C) nutrient space, showing growth (biomass) is protein-limited while immune traits (hemocyte counts, phenoloxidase activity) peak at intermediate P:C ratios distinct from the growth optimum. Survival after Bacillus thuringiensis challenge tracked protein intake specifically, and antioxidant/detoxification enzyme responses varied non-linearly and non-uniformly across the nutrient landscape. This demonstrates trait-specific rather than universal nutritional optima, a finding replicable via response-surface/GF designs in other insect systems and relevant to integrated pest management (e.g., optimizing host-plant nutrient content to suppress pest immunity or stress tolerance).

bioRxiv · ecologyConceptual

The consequences of mixed-mode transmission for disease prevalence

Diseases that spread two different ways don't automatically become more common — it depends on the trade-offs.

Parasites and pathogens spread between hosts in different ways: some depend on crowding (density-dependent, like a cold spreading faster in a packed room), others spread at a steady rate no matter how many hosts are around (frequency-dependent, like an STI). Many real diseases actually use both routes at once, so this study built a model to ask whether combining transmission modes makes outbreaks worse. Using a mathematical model with a built-in trade-off (getting better at one transmission route means getting worse at the other), the researchers simulated infection spread under single versus mixed strategies. Surprisingly, mixing modes only boosts how common a disease becomes when the two routes also affect the host's health or reproduction differently — otherwise mixing transmission strategies gives no special advantage, which reshapes how epidemiologists should think about multi-route diseases like some sexually transmitted or environmentally persistent infections.

Technical view

The authors build an epidemiological model comparing single-mode (purely density- or frequency-dependent) versus mixed-mode transmission under an imposed linear trade-off between infection probabilities via each route, then compare equilibrium prevalence. Key result: mixed-mode transmission only exceeds single-mode prevalence when the two transmission routes differentially affect host fitness (e.g., differing virulence or fecundity costs per route); absent that fitness asymmetry, mixing modes confers no prevalence advantage over the best single mode. This is a useful null result for modelers of STIs, vector-borne, or environmentally transmitted pathogens — it suggests searching for route-specific fitness costs before attributing high prevalence to transmission-mode diversity per se.

bioRxiv · ecologyRunnable

Field persistence of entomopathogenic fungi and network-level associations within the soil microbial community as biocontrol agents

Fungal 'bio-pesticides' protect date palms from a deadly weevil for six months without wrecking soil life.

The red palm weevil is a devastating pest of date palms, and instead of chemical pesticides, researchers tested two natural fungi that infect and kill insects (entomopathogenic fungi) as a preventive treatment. They applied the fungi to palm soil, then tracked how long the fungi survived, how well they protected the trees, and — crucially — whether they disrupted the broader community of microbes living in the soil, using genetic sequencing and lab culturing. Both fungal species stuck around in the soil for a full 180 days and meaningfully reduced weevil damage, though one (Beauveria bassiana) gave longer-lasting protection than the other. Reassuringly, the overall soil microbial community stayed largely intact, suggesting these fungi can be used as an environmentally friendly pest control tool without collateral damage to soil ecosystems.

Technical view

Researchers applied Metarhizium brunneum and Beauveria bassiana as preventive soil treatments against Rhynchophorus ferrugineus on date palms, quantifying fungal persistence via culture-based isolation and high-throughput metagenomic sequencing of soil microbiota over 180 days, alongside continuous palm health monitoring. Both EPF species persisted for the full 180-day window and significantly reduced weevil damage, with B. bassiana outperforming M. brunneum in duration of protection despite comparable persistence; critically, metagenomic community-level analysis showed no major shifts in overall soil microbiome composition post-application. This supports EPF as a non-disruptive biocontrol option for palm plantations and provides a persistence/efficacy benchmark (180-day window) and a metagenomic protocol for assessing off-target microbiome effects in future biocontrol deployments.

bioRxiv · geneticsConceptual

When Does Reaction Norm GWAS Discover Plasticity? The Residual Channel in Environmental Index-Based Genetic Dissection

A popular gene-hunting method for 'flexible' traits is mathematically blind to the very flexibility it claims to find.

Plants and animals often show plasticity — the ability to change their traits depending on the environment — and scientists want to find the genes behind that flexibility using a statistical method called CERIS-JGRA, which builds a climate-based 'environmental index' to compare against average performance. This paper is a critique: it shows mathematically that the way the index is constructed forces it to closely track the environmental average, which is exactly the wrong thing if you want to isolate plasticity (the part of the response that's independent of the average). The authors prove that the more correlated the index is with the mean, the less room is left for it to capture true plasticity signal, and they confirm this shortfall with simulations. The takeaway is a cautionary one for genetics: a widely used tool for finding 'flexibility genes' may be systematically weak at its core job, so scientists need to rethink how they build these environmental indices.

Technical view

The paper formally analyzes CERIS-JGRA, a reaction-norm GWAS method that substitutes a climate-derived environmental index for the Finlay-Wilkinson environmental mean. It proves that an index with correlation ρ to the true environmental mean decomposes as ρ·(mean) + residual, meaning its loading τ on mean-orthogonal (plasticity-relevant) variation is bounded by √(1−ρ²) — and since the algorithm is constructed to maximize ρ, it necessarily minimizes τ, and thus the non-centrality of any plasticity-specific association test (which scales as τ²). Simulations across 189 conditions confirm this predicted power loss with a parameter-free closed-form expression matching observed results. Practically, this implies GWAS practitioners using CERIS-JGRA-style indices should decouple index construction from mean-correlation maximization if they want statistical power to detect genotype-by-environment/plasticity loci rather than just mean-performance loci.

bioRxiv · biochemistryBuildable

Computational evolutionary approach to generate antimicrobial peptides

AI redesigns a fish toxin into a smarter antibiotic-resistant bacteria killer.

Antibiotics are losing their power because bacteria keep evolving resistance to them, so scientists are hunting for entirely new kinds of weapons. One promising class is antimicrobial peptides — short chains of amino acids that punch into bacterial membranes rather than working like traditional drugs. Here researchers started with pardaxin, a peptide from fish that already damages bacterial membranes, and used an AI protein-language model (like a spellchecker trained on millions of proteins) to suggest small swaps in its sequence that might make it even better at killing germs like E. coli and Staph. Combining the AI's suggestions with established peptide-design rules let them narrow down which tweaked versions are worth testing in the lab, speeding up the search for the next generation of infection fighters.

Technical view

The team performed in silico point-mutation scans on the antimicrobial peptide pardaxin, using embeddings from ESM Cambrian (ESMC), a protein language model, to score candidate substitutions alongside conventional AMP design heuristics (e.g., amphipathicity, net charge, hydrophobic moment). Principal component analysis on the ESMC embedding space was used to identify single- and likely multi-substitution variants clustering toward regions associated with improved membrane-disruptive activity. This embedding-plus-rules pipeline offers a template other groups could reuse to triage AMP variant libraries computationally before committing to synthesis and MIC assays against pathogens like S. aureus and E. coli.

bioRxiv · biochemistryRunnable

Coupling Luciferase Activation and BRET Enables High-Contrast Red-Window Calcium Imaging

A glowing protein flashes 55x brighter in red light whenever calcium surges in cells.

Scientists studying brain and cell activity often want to watch calcium ions flowing in and out of cells, since that flow signals things like neurons firing. Normally this requires shining light on the tissue to make a fluorescent marker glow, but that light can damage tissue and doesn't penetrate deep. This team built a molecule called HyBRIC that instead makes its own light — bioluminescence, like a firefly — and combined two tricks: an enzyme (luciferase) that switches on with calcium, and an energy-transfer relay that shifts the glow into red light, which passes through tissue much better than other colors. The result is a calcium sensor that lights up roughly 55 times brighter when calcium rises, giving researchers a clearer, deeper, excitation-free window into living cells.

Technical view

HyBRIC and HyBRIC2 are genetically encoded bioluminescent Ca2+ indicators that couple Ca2+-dependent luciferase activation with bioluminescence resonance energy transfer (BRET) to shift emission into the red optical window, where tissue absorption/scattering is minimized. Using the luciferin substrate pyCTZ, the sensors achieve ~55-fold Ca2+-dependent signal increases in vitro, with HyBRIC2 offering improved brightness and response kinetics over HyBRIC in mammalian cells. This addresses the historically low dynamic range of bioluminescent indicators relative to fluorescent GCaMP-type sensors, and the modular BRET/luciferase-activation architecture is a design a lab could adapt to other analytes or luciferin variants for deeper, excitation-free in vivo imaging.

bioRxiv · bioengineeringConceptual

An integrated biomaterials-centred approach of the ageing thymic microenvironment reveals design principles for regenerative biomaterials

Old thymus tissue gets ten times stiffer — and that clue could guide lab-grown immune organs.

The thymus is the organ that trains your immune system's T-cells, but it shrinks and weakens dramatically as we age, a process called involution. Rather than just looking at which cells disappear, this study treated the thymus like a material — measuring its stiffness, its chemical makeup, and the arrangement of fats and minerals inside it — by comparing young and old cow thymus tissue with lab techniques like rheology (squishiness testing) and mass spectrometry imaging (a chemical map). They found aged thymus tissue becomes dramatically stiffer and more brittle, and its fat composition shifts, especially toward fat-storage molecules called triacylglycerols. Understanding these physical and chemical changes gives engineers a blueprint for building artificial thymus-like materials that could one day help restore immune function in older or immunocompromised people.

Technical view

The authors characterized young versus aged bovine thymus using histology, oscillatory rheology, untargeted lipidomics, ICP-MS, and AP-MALDI mass spectrometry imaging to build an integrated mechanical-compositional-spatial profile of thymic involution. Aging increased both storage and loss moduli by over an order of magnitude while narrowing the linear viscoelastic region ~5-fold, indicating a much stiffer, more strain-sensitive tissue state, accompanied by lipidomic remodeling (notably a doubling of triacylglycerol contribution to the lipid pool). These quantitative benchmarks — stiffness ranges, viscoelastic limits, lipid ratios — provide target design parameters for engineers building thymus-mimetic scaffolds or hydrogels intended for immune tissue regeneration.

bioRxiv · bioengineeringBuildable

A Modular Bio-Hybrid Skin Model for Optical Testing Applications

A living-synthetic hybrid 'skin' lets scientists test sunscreens without animals or guesswork.

Testing sunscreens, cosmetics, and medical light-based devices usually means either using synthetic fake skin, which behaves predictably but isn't truly biological, or lab-grown living skin, which is realistic but varies too much between batches to trust for precise measurements — and increasingly, companies want to avoid animal testing altogether. This paper builds a middle-ground: a modular 'bio-hybrid' skin made of an engineered artificial top layer — using color-changing nanoparticles to mimic different skin tones — layered with real living human skin cells (keratinocytes) underneath. In one demonstration, they shine UV-B light on it and measure the resulting cell death, mimicking sunburn damage, to show the model can quantitatively capture real biological injury from light exposure. This gives researchers a tunable, reproducible, animal-free platform to test how light-based technologies affect real human skin.

Technical view

The bio-hybrid skin model combines an optically engineered synthetic epidermal layer — polydopamine nanoparticles tune melanin-like optical absorption to represent different skin tones — with living primary human keratinocytes cultured in 2D and 3D configurations, aiming to merge the reproducibility of synthetic optical phantoms with the biological authenticity of tissue-engineered skin. In their 'Optical Protection Model,' the team quantified UV-B-induced apoptosis in the keratinocyte layer, demonstrating that the construct can serve as a dose-response readout for phototoxicity and photoprotection testing. This modular architecture is positioned as an animal-free validation platform for optical biomedical devices (e.g., sunscreens, phototherapy, diagnostic optical sensors), and the polydopamine-tone-tuning approach could be extended to model diverse skin pigmentation in device safety testing.

bioRxiv · bioengineeringRunnable

DCGAN-Based Synthetic MRI Augmentation for Data-centric Brain Tumor Segmentation

Fake AI-generated brain scans help teach tumor-finding software with less real patient data.

Training AI to spot brain tumors in MRI scans normally needs thousands of scans that a doctor has painstakingly outlined by hand, which is expensive and slow to produce. This study tests a shortcut: using a generative AI model (a DCGAN, a type of network that learns to produce realistic fake images by having two networks compete against each other) to manufacture extra synthetic brain MRI images. They then auto-generate approximate tumor outlines for these fake images and mix them into the training set for a tumor-segmentation AI called U-Net, comparing performance against a version trained only on real data. The question they're answering is whether 'padding' a small real dataset with AI-generated synthetic examples meaningfully improves how well the segmentation model finds tumors on new, unseen scans.

Technical view

The authors trained a DCGAN on the LGG-MRI dataset (3,929 image-mask pairs) to generate synthetic brain MRI slices, then produced pseudo-segmentation masks for these synthetic images via thresholding, creating an augmented training corpus for a U-Net tumor-segmentation baseline. They compare segmentation performance (presumably Dice/IoU) between a U-Net trained on the original dataset alone versus one trained on the GAN-augmented set, evaluated on a held-out real test split. This is a data-centric AI study — the contribution is empirical evidence on whether GAN-synthesized images with heuristic pseudo-labels are a viable low-cost substitute for expert-annotated data in low-resource medical segmentation pipelines.

bioRxiv · bioengineeringBuildable

Self-Actuating 4D Cell-Strand Bioprinting

Bioprinted living tissue folds and morphs into shape on its own, powered only by its own cells.

When your body builds tissues during development, cells don't just sit still — they physically pull and push on their surroundings to sculpt complex 3D shapes, a process called morphogenesis. Standard 3D bioprinting produces static structures, but this work creates a '4D' bioprinting platform, meaning the printed structure keeps changing shape over time after printing, entirely on its own. The trick is printing dense strands of living cells inside a temporary scaffold material that quickly dissolves; as it dissolves, the cells connect into networks and use their own natural contracting force — the same kind of pulling cells do inside real tissue — to bend and reshape the surrounding soft gel into a programmed final form, with no external triggers like heat or light needed. By controlling where the cell strands are placed, researchers can essentially program the tissue's contraction to fold into custom-designed shapes, opening a path to building more lifelike, self-organizing tissue structures for research or transplantation.

Technical view

The platform prints high-density cell strands using a fast-degrading sacrificial carrier bioink embedded within a mechanically compliant, self-softening base hydrogel. As the carrier degrades during culture, cells proliferate and form interconnected networks whose endogenous cellular contractile force (CCF) drives autonomous, spatially programmable shape morphing of the surrounding hydrogel — a genuinely self-actuating 4D system requiring no external stimuli (light/heat/pH) to trigger shape change, unlike most existing 4D bioprinting approaches. Spatial patterning of the embedded cell-strand geometry acts as the design parameter for the final morphed architecture, suggesting a generalizable strategy for engineering tissues that recapitulate developmental folding/morphogenesis for regenerative or disease-modeling applications.

bioRxiv · bioengineeringBuildable

Bio-CM{superscript 2}: Distributed computational optics for cortex-widecellular imaging

Four tiny cameras team up on one head-mounted chip to film a mouse's whole brain surface at once.

Neuroscientists want to watch individual brain cells firing across a large area of the brain's surface at once, ideally with a lightweight camera small enough for a moving animal to wear. The problem is that miniature microscopes force a tradeoff: you can see a wide area or you can see fine cellular detail, but existing optics struggle to do both without becoming bulky and complicated. This team's solution splits the job across four separate small optical 'modules,' each capturing a piece of the field of view, and then uses computation to digitally stitch their measurements back together into one sharp, wide image on a shared sensor — essentially trading some optical complexity for computing power. The result, called Bio-CM2, aims to let scientists image cellular activity across a much larger swath of the brain's cortex than typical miniature microscopes allow, without sacrificing sharpness.

Technical view

Bio-CM2 implements 'distributed computational optics,' partitioning the imaging field-of-view across four coordinated miniature optical modules that each capture a sub-FOV onto a shared image sensor, with computational reconstruction integrating the multi-module measurements into a single cellular-resolution, millimeter-scale image. This architecture sidesteps the aberration-scaling problem that limits conventional single-lens miniature microscopes as FOV grows, while avoiding the bulk/complexity of multi-sensor or scanning-based wide-FOV systems. The approach is relevant to anyone building head-mounted or wearable mesoscopes for freely behaving animal imaging, offering a modular hardware+computational-reconstruction template for scaling FOV without proportionally scaling optical complexity or device weight.

bioRxiv · bioinformaticsRunnable

ProNA3D: Distance-Based Analysis of Nucleic Acid-Containing Interfaces

A new tool maps exactly how RNA and DNA physically touch proteins, even in AI-predicted structures.

Many crucial cell processes depend on RNA or DNA physically interacting with proteins, but figuring out the precise 3D shape of these interactions has been historically hard, even though AI tools like AlphaFold3 now predict more of these structures than ever. The problem is that once you have a structure — whether solved by experiment or predicted by AI — there hasn't been a good, unified tool to actually analyze and make sense of how the pieces are touching. ProNA3D fills that gap: it's a software platform that takes these protein-nucleic acid structures and measures the distances and contacts at their interface, scores how trustworthy AlphaFold3's predictions are, and produces visual maps (both 2D diagrams and secondary-structure diagrams) so researchers can interpret exactly where and how the molecules interact, including inside blurry cryo-EM density maps.

Technical view

ProNA3D is an analysis platform for protein–nucleic acid and nucleic-acid-only complex interfaces that accepts both experimentally solved and computationally predicted (including AlphaFold3) structures, incorporating AF3-specific confidence/scoring metrics into its interface analysis. It performs distance-based interface characterization with interactive 2D interface maps and RNA/DNA secondary-structure topology plots, plus an interface-based density-zoning feature for evaluating dynamic or ambiguous regions directly within cryo-EM maps. For structural biologists, it functions as a post-prediction/post-solving analysis layer — bridging AlphaFold3-era structure generation with functional interface interpretation that previously required stitching together multiple disparate tools.

bioRxiv · cancer biologyConceptual

A p53-dependent FBXO44-RAD18 axis limits mutagenesis by terminating translesion DNA synthesis

A cellular "off switch" halts error-prone DNA repair once it's no longer needed, blocking extra mutations.

When DNA gets damaged, cells have a backup copying system called translesion synthesis (TLS) that lets them push through the damage instead of stalling — but this backup system is sloppy and makes mistakes. Researchers found a protein pair, FBXO44 and RAD18, that acts like a brake: once the danger has passed, FBXO44 tags RAD18 for disposal, shutting the risky repair pathway back down. This shutdown is controlled by p53, the well-known "guardian of the genome" protein, which activates FBXO44 later in the stress response. Without this brake, cells accumulate more mutations, which can fuel cancer — so understanding it could reveal new ways to exploit this vulnerability in tumors.

Technical view

Using transcriptional profiling, genome-wide CRISPR/Cas9 screens for replication-stress sensitivity, and proteomics, the authors identify FBXO44 as a late p53 target gene that terminates translesion DNA synthesis (TLS). FBXO44 acts as an F-box substrate receptor that ubiquitinates RAD18, the E3 ligase responsible for PCNA monoubiquitination that licenses TLS polymerase recruitment, triggering RAD18 turnover during recovery from replication stress. This creates a temporally restrained circuit: p53 activation induces FBXO44 to shut down RAD18-PCNA-Ub signaling once lesion bypass is complete, limiting persistent error-prone synthesis. Loss of this axis is predicted to raise mutagenesis and could be probed as a synthetic-lethal vulnerability in p53-proficient, TLS-dependent tumors.

bioRxiv · physiologyRunnable

Semenogelin-1 Inhibition of Mouse Sperm Hyperactivation Reveals Two Functional Domains Modulating CatSper Channel

A seminal fluid protein throttles sperm's turbo-swim mode by plugging a calcium channel, piece by piece.

After ejaculation, sperm are temporarily "put to sleep" by a seminal fluid protein called semenogelin-1 (SEMG1), which stops them from developing the vigorous whip-like swimming (hyperactivation) needed to fertilize an egg — until later processing frees them up. This study asked how SEMG1 pulls this off, and found it directly blocks a calcium channel called CatSper on the sperm's tail that's essential for that power-swimming behavior. By testing the full protein versus fragments of it, the researchers pinpointed two separate regions of SEMG1 that each help shut the channel down. Understanding this molecular brake could explain natural fertility control and inspire new non-hormonal contraceptive approaches.

Technical view

The authors used recombinant full-length mouse SEMG1 (Q32-G375) and truncated fragments with patch-clamp electrophysiology to show SEMG1 directly inhibits CatSper, the sperm-specific principal calcium channel required for hyperactivated motility, at physiologically relevant concentrations. Because NH4Cl-induced alkalinization failed to rescue hyperactivation, the inhibitory mechanism acts downstream of the pH-dependent CatSper activation step rather than blocking capacitation-associated alkalinization itself. Domain-mapping with truncated constructs identified two distinct functional regions each contributing to CatSper current suppression, suggesting a multi-site inhibitory mechanism. This establishes CatSper as a direct pharmacological target of seminal plasma regulation, offering a template for CatSper-modulating non-hormonal contraceptives or fertility diagnostics.

bioRxiv · plant biologyConceptual

Breakdown of sporophytic self-incompatibility: Diploids versus tetraploids

Doubling a plant's chromosomes makes it much easier to break its "no self-fertilizing" rule.

Many flowering plants have a genetic self-incompatibility system that stops them from fertilizing themselves, which keeps genetic diversity high — but scientists have noticed that plants with doubled chromosome sets (tetraploids, versus normal diploids) tend to self-fertilize more often. This study used mathematical models and computer simulations to test how easily a new "self-compatible" mutation can invade and spread in populations with one versus two chromosome copies. They found the self-incompatibility system is inherently more fragile in tetraploids, and that the pecking order of which genetic variants dominate over others strongly affects how fast the system collapses. This helps explain plant evolution and crop breeding patterns, including why genome duplication (common in plant history) so often coincides with a shift toward self-fertilization.

Technical view

Using analytical population-genetic models and individual-based simulations, the authors compare invasion dynamics of a self-compatible (SC) allele into sporophytic self-incompatibility (SSI) systems in diploid versus tetraploid populations, under both codominant and hierarchically-dominant SI allele architectures. The core result: SSI breakdown is systematically easier in tetraploids than diploids, and increasing the dominance rank of the invading SC allele further accelerates its fixation. The dominance-class scenario shows that segregation and expression patterns unique to autotetraploid genetics (more allele combinations per genotype) weaken effective self-recognition. This provides a quantitative framework linking ploidy-driven dominance/segregation changes to the empirically observed correlation between polyploidy and elevated selfing rates in angiosperms.

bioRxiv · plant biologyConceptual

Leaf hydraulics is a core component of plant immunity

Leaf pores meant to release water double as bacterial front doors — and as flood barriers against infection.

Plant leaves have tiny water-releasing structures at their edges called hydathodes, which ooze out excess water (guttation) — but they're also a favorite entry point for certain leaf-attacking bacteria. Researchers engineered Arabidopsis plants with fewer hydathodes and found something surprising: instead of being protected, these plants got internally waterlogged and let bacteria multiply out of control by sneaking in through other pores called stomata. Physically clogging hydathodes caused the same waterlogging and infection boost in both Arabidopsis and cauliflower. The takeaway: hydathodes aren't just infection risks, they're essential drainage valves that prevent leaf tissue from flooding, and that flooding is what lets bacteria run rampant — showing a plant's internal plumbing is a core part of its immune defense.

Technical view

Hydathodes are xylem-connected structures at Arabidopsis leaf margins that mediate guttation and serve as known infection portals for vascular pathogens like Xanthomonas campestris. The authors show Arabidopsis mutants with reduced hydathode numbers develop spontaneous mesophyll water-soaking upon infection and support unexpectedly large bacterial populations, driven by pathogen entry through stomata and proliferation directly in the water-soaked mesophyll niche rather than the vasculature. Physical occlusion of hydathodes reproduced both water-soaking and enhanced bacterial growth in Arabidopsis and cauliflower, causally linking hydraulic dysfunction to loss of nonvascular tissue resistance. This establishes leaf hydraulic regulation as an active component of "water immunity," suggesting hydathode function or water-soaking resistance as a novel breeding target for bacterial disease resistance.

bioRxiv · systems biologyBuildable

Beige/brown fat-mediated cardiac protection from high-fat diet is dependent on adipocyte beta3-adrenergic receptor

A fat-cell "burn switch" that turns fat into heat also seems to shield the heart from a fatty diet.

Obesity-related heart disease is a huge health problem, and one hope for treatment lies in brown and "beige" fat — special fat tissue that burns calories as heat instead of storing them, activated through a receptor called beta3AR. This study genetically removed beta3AR specifically from fat cells in mice, then fed them a high-fat, high-sugar diet, with some treated with a drug that normally activates this receptor, to test whether the receptor is truly necessary for fat-burning's heart-protective benefits. Proving the fat cells themselves (not some other organ) are responsible for protecting the heart opens the door to drugs that specifically target fat tissue to prevent obesity-related heart damage. This matters because current treatments for obesity-linked heart problems aren't very effective, and this points to a specific druggable pathway.

Technical view

The authors used adipocyte-specific beta3-adrenergic receptor (beta3AR) knockout mice challenged with a high-fat-sucrose (HF-S) diet, with and without the selective beta3AR agonist CL316,243, to test whether adipocyte beta3AR is required for beige/brown fat-mediated cardiometabolic protection. Beta3AR normally drives adipose tissue lipolysis and BAT thermogenesis, and pharmacological activation induces beiging of white adipose depots — a pathway of therapeutic interest given BAT's limited abundance in aged/obese humans. The genetic deletion isolates adipocyte-autonomous beta3AR signaling from systemic or cardiac-intrinsic drug effects, directly testing whether cardiac metabolic/structural protection depends on this receptor in fat cells specifically. Results should clarify whether beta3AR agonists' cardioprotective effects in obesity are mediated via adipose remodeling, informing whether adipose-targeted versus cardiac-targeted agonism is the better drug strategy.

bioRxiv · systems biologyBuildable

Unlocking substrate specificities of human solute carrier proteins using untargeted metabolomics

Scientists dunked cells carrying mystery transporter proteins into human blood to catch what they actually shuttle around.

Solute carrier proteins (SLCs) are a huge family of "doorways" in cell membranes that shuttle nutrients, drugs, and waste in and out of cells, but for many of them we don't know what molecules they actually carry — unidentified locks without known keys. Researchers put frog egg cells (a classic tool for testing one protein at a time) engineered to make a single human SLC transporter each into human blood serum, packed with thousands of real biological molecules, then used a sensitive chemical detection method (mass spectrometry) to see which molecules vanished from outside and appeared inside the cell, or vice versa. This let them match five specific transporters to the substances they actually move, "deorphanizing" proteins whose job was previously unknown. Since these proteins govern nutrient absorption, drug delivery, and disease, mapping what each one moves could reveal new drug targets or explain unwanted drug interactions.

Technical view

The authors developed a Xenopus oocyte-based screening platform in which oocytes heterologously expressing individual human SLC transporters are incubated in human serum — a complex, physiologically relevant metabolite library — followed by paired untargeted LC-MS/MS profiling of both intracellular extracts and surrounding medium to detect metabolite depletion/accumulation signatures indicative of transport activity. Applied to five transporters (SLC10A2, SLC10A6, SLC13A2, SLC16A10, SLC46A1), the method detected characteristic exchange signatures, with automated feature annotation refined by manual chromatographic/spectral review to assign putative substrates. This sidesteps the need for pre-selected candidate substrate panels, enabling unbiased deorphanization against physiological metabolite complexity rather than synthetic buffers. The platform is generalizable to any cloneable SLC and could scale to map substrate spectra across the ~400-member human SLC superfamily, informing drug-transporter interaction and nutrient biology studies.

bioRxiv · systems biologyBuildable

Cross-Species Efficacy of Combinatorial Gene Therapy for Osteoarthritis and Correction of Neuro-Inflammatory Pain Mechanisms

A two-gene injection eased arthritis pain and joint damage in both mice and full-size horses.

Osteoarthritis causes chronic joint pain and disability, and there's currently no treatment that actually slows the disease rather than just masking symptoms. Because the disease involves multiple problems at once — inflammation and breakdown of cartilage-protecting cells — researchers built a gene therapy delivering two therapeutic genes at once (one to calm inflammation, one to support joint-cushioning cells) via a viral carrier injected directly into the joint. They tested this in both mice and horses, which is notable because horse joints are much closer in size and mechanics to human joints, making it a far stronger real-world test than mice alone. The treatment improved joint structure, movement, and pain, and even calmed inflammation-related pain signaling in the nerve clusters carrying pain messages from the joint — suggesting it could become a long-lasting, disease-modifying treatment for arthritis pain in humans.

Technical view

The therapy uses a high-capacity (helper-dependent) adenoviral vector co-expressing two transgenes — IL-1Ra (an interleukin-1 receptor antagonist targeting inflammation) and PRG4/lubricin (supporting chondrocyte health and cartilage lubrication) — delivered via intra-articular injection. Efficacy was demonstrated across both murine and equine osteoarthritis models, with the equine model providing large-animal, biomechanically human-relevant validation uncommon in OA gene therapy studies. Beyond local joint outcomes (functional, structural, pain metrics), treatment normalized inflammatory gene/protein signatures in joint tissue and in the dorsal root ganglia (DRG) housing joint-innervating sensory neurons, indicating a peripheral neuro-immune mechanism for pain reversal rather than purely local anti-inflammatory action. The dual-transgene, single-vector, intra-articular design and cross-species efficacy data position this as a translatable disease-modifying OA candidate ready for further large-animal/clinical-stage development.

bioRxiv · systems biologyBuildable

Proteome-wide QTL mapping enables gene-protein-phenotype metabolic network construction in a genetically diverse MASLD mouse model

Breeding genetically mixed mice and scanning their liver proteins maps the hidden circuitry behind fatty liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD, commonly called fatty liver disease) affects an enormous share of adults worldwide, but treatments are limited because scientists don't fully understand the tangled web of genes and proteins driving it. To untangle this, researchers cross-bred four mouse strains that vary in liver disease susceptibility, producing hundreds of genetically diverse offspring, then measured thousands of liver proteins in each mouse alongside its genetic makeup and disease symptoms. By statistically linking specific genetic variants to specific protein levels (quantitative trait loci, or QTLs), they built a map of which genes directly control which proteins, and which of those connections ripple out to affect disease-related traits. This gene-protein-phenotype network gives researchers a roadmap of candidate genes and proteins to test as potential drug targets for fatty liver disease.

Technical view

The authors generated a four-way founder cross of 444 F2 mice with genetically diverse liver disease susceptibility, then performed deep quantitative proteomic profiling of livers paired with genotyping to map protein quantitative trait loci (pQTLs). They identified QTLs for 2,652 proteins across more than 4,000 unique genomic loci, distinguishing cis-acting (local, likely direct genetic control) from trans-acting (distal, likely network-mediated) regulatory loci. Integration of proteomic, genomic, and phenotypic data enabled construction of gene-protein-phenotype networks, nominating candidate regulatory genes and proteins underlying MASLD trait variation. This resource-scale pQTL dataset provides a systems-genetics framework and candidate gene list other researchers can mine for causal driver validation, functional follow-up, or cross-referencing against human MASLD GWAS/proteomics data.

bioRxiv · zoologyConceptual

Seasonal hepatic plasticity follows a temporal response hierarchy in a Neotropical frog

A frog's liver keeps a seasonal diary, and its cells write the first draft.

This study follows a small Brazilian treefrog through a full year to see how its liver changes with the seasons. Researchers looked at four levels of the liver at once: tiny chemical stores inside cells, the shape of individual cells, how the tissue as a whole is arranged, and the size of the whole organ relative to the body. The idea they're testing is whether change ripples outward in order — starting at the smallest, fastest-reacting level (inside cells) and only later showing up at the whole-body level. Understanding this hierarchy matters because it tells biologists how animals sense and buffer environmental swings like wet and dry seasons, which is increasingly relevant as climates shift unpredictably.

Technical view

The authors sampled 40-68 wild adult male Dendropsophus minutus across an annual cycle and quantified four hepatic phenotypic modules — intracellular histochemistry (pigment/glycogen stores), cellular morphometry, tissue-level volumetric composition (hepatocytes, sinusoids, melanomacrophage centres, portal structures), and organismal indices (liver mass, body condition) — to test for a predictable temporal response hierarchy across organizational levels. The core hypothesis is that lower organizational levels (intracellular/cellular) exhibit faster, more immediate seasonal responses than higher levels (tissue/organismal), which would lag or integrate cumulative change. This design offers a replicable multi-level framework for other ectotherm field studies aiming to disentangle rate-dependent physiological plasticity from mere seasonal correlation.

bioRxiv · neuroscienceConceptual

Language-aligned models and structured scene descriptions reveal sensitivity to compositional scene structure in the high-level visual cortex

Your brain seems to read the 'grammar' of a scene, not just list the objects in it.

When you look at a photo, you don't just notice a dog and a ball separately — you understand the dog is chasing the ball. This study asks whether the brain's visual areas actually encode that kind of relationship, not just a checklist of objects and words. Researchers fed the brain (via detailed brain scans while people viewed images) either full descriptive sentences about scenes or the same words scrambled into a meaningless jumble, then checked which one better matched brain activity. The full, structured sentences predicted brain responses better, especially for busy, relationship-rich scenes — and an AI model trained on both language and images did a better job explaining this than a vision-only AI. It matters because it suggests our sense of a coherent scene is built into visual perception itself, not bolted on afterward by language.

Technical view

Using 7T fMRI from the Natural Scenes Dataset, the authors built encoding models relating cortical responses to narrative scene descriptions versus word-order-scrambled lexical controls that preserve content words but destroy compositional syntax. Intact narratives predicted high-level visual cortex responses better than scrambled controls, with the advantage scaling with a scene's compositional richness, indicating the region encodes relational/compositional structure beyond a bag-of-words object list. A language-aligned vision model (trained with both visual and linguistic supervision) outperformed a self-supervised vision-only model at capturing this structure, suggesting language-alignment during training instills representations closer to how visual cortex organizes scene relations — a testable target for future multimodal model-brain alignment work.

bioRxiv · immunologyConceptual

Gelsolin Counteracts ER Stress-Driven Inflammatory Circuits in Psoriasis-like Dermatitis

A stressed-out cell factory inside immune cells may be secretly fueling psoriasis flare-ups.

Psoriasis is a skin condition where immune cells and skin cells send inflammatory signals back and forth in a vicious cycle. This research shows that a common psoriasis-triggering chemical stresses out a cell's internal protein-folding factory (the endoplasmic reticulum, or ER) inside immune cells called dendritic cells, causing contact points to form between the ER and the cell's energy-producing mitochondria. That stress response boosts production of an inflammatory signal (IL-23) and also leaks out mitochondrial DNA and calcium, which further rev up inflammation through a separate alarm system. Meanwhile skin cells under the same stress make an antimicrobial protein that, together with the leaked DNA, activates yet another set of immune cells — building a self-reinforcing inflammatory loop. Mapping this loop matters because it reveals new points, beyond current psoriasis drugs, where treatment could interrupt the cycle.

Technical view

In a murine imiquimod (IMQ)-induced psoriasis-like dermatitis model, IMQ drives ER-mitochondria contact site (MAM) formation and UPR activation in dendritic cells, which enhances IL-23 expression independently of but convergent with TLR7/MyD88 signaling; concurrently, elevated cytosolic Ca2+ activates the NLRP3 inflammasome, releasing mitochondrial DNA. Keratinocytes exposed to IMQ upregulate UPR-dependent genes including the antimicrobial peptide Defb14/mBD14, and extracellular mtDNA plus mBD14 cooperatively engage plasmacytoid dendritic cells via TLR9, closing an amplification loop. This positions ER stress/UPR and MAM signaling as a mechanistic node upstream of IL-23 and TLR9 activation, offering candidate targets (e.g., UPR inhibitors, MAM disruptors) for combination therapy alongside existing IL-23-axis biologics like the gene mentioned Gelsolin counteracting this circuit.

bioRxiv · immunologyConceptual

Wobble Vaccines: Complex Vaccine Antigen Pools Promote Increased Antibody Breadth and Cross-Strain Viral Targeting in SARS-CoV-2

Deliberately messy vaccines might out-evolve fast-mutating viruses like COVID.

Viruses like the one causing COVID keep changing shape to dodge our immune defenses, so vaccines built for one version can lose effectiveness. This project tries a counterintuitive fix: instead of targeting the virus's usual weak spots, build an mRNA vaccine (the same technology behind many COVID shots) that deliberately mixes in many different, less-common versions of the virus's surface protein. The goal is to nudge the immune system toward attacking parts of the virus that are less likely to mutate away, a strategy the researchers call 'rare epitope suppression.' They analyzed two years of public COVID genetic sequencing data to find the sites on the virus that vary the most, then designed their 'wobble vaccine' around that diversity. If it works, it could mean vaccines that stay effective longer against a shape-shifting virus, cutting down the need for constant reformulation.

Technical view

The authors mined public SARS-CoV-2 sequence data from the pandemic's first two years to identify high-diversity epitope sites, then designed mRNA-based 'wobble vaccines' — complex antigen pools incorporating multiple variant sequences at those sites — to apply 'rare epitope suppression' (RES), redirecting humoral immunity away from hypervariable immunodominant epitopes toward more conserved regions. The claim is that this pool-based antigen design broadens antibody targeting and improves cross-strain neutralization compared to single-strain vaccines. This is a platform-level approach that could be replicated for other rapidly evolving pathogens (e.g., influenza) by substituting pathogen-specific diversity-mapped antigen sets into the same mRNA delivery framework.

bioRxiv · molecular biologyConceptual

New histone deposition recruits the DNA methylation maintenance machinery at sites of DNA damage repair

Cells caught rewriting DNA damage also relabel it with the same chemical tags it had before.

Our DNA carries not just the genetic code but also chemical 'sticky notes' called methylation marks that tell cells which genes to use — and these marks need to be faithfully copied every time DNA is repaired or replicated, or cells can lose track of their identity. This study looks at what happens to those marks when DNA gets damaged by UV light (like sunburn-causing rays) and then repaired. The researchers found that cells actually preserve most of the original marks during repair, and they identified the specific molecular crew responsible: two 'marking' enzymes get recruited to damage sites, guided by a helper protein and the repair machinery itself. They also found that fresh copies of a structural protein called a histone, deposited right at the damage site, help recruit this whole marking crew. This matters because losing methylation marks incorrectly is linked to cancer and other diseases, so understanding how cells protect this memory during repair could reveal new angles on disease risk.

Technical view

Using sequencing, imaging, and proteomics in mammalian cells subjected to UV damage, the authors show that DNA methylation is largely preserved during nucleotide excision repair-associated synthesis, and they identify recruitment of DNMT1 and DNMT3A to repair sites, driven by the DNMT1 cofactor UHRF1 together with UV damage repair endonucleases. They further demonstrate a mechanistic link to chromatin dynamics: newly deposited H3.3 histones at damage sites help recruit this methylation-maintenance machinery, extending the known replication-fork paradigm (where UHRF1/DNMT1 maintain methylation) to a DNA-damage-repair context. This establishes damage-repair synthesis as a second genomic context requiring active methylation maintenance, suggesting UHRF1/DNMT1/H3.3 dynamics as candidate targets for probing epigenetic instability in damage-prone or repair-deficient tissues.

bioRxiv · molecular biologyBuildable

Sequential intra-articular HCAd-NFκB-IL-1Ra delivery improves therapeutic efficacy in post-traumatic osteoarthritis

One shot of gene therapy calms an arthritic knee for a while — then needs a disguised sequel.

Osteoarthritis, the wear-and-tear joint disease, has no treatments that actually slow its progression — only ones that manage pain. This study tests a gene-therapy approach in mice with injury-induced knee arthritis: injecting a modified virus directly into the joint that delivers instructions for cells to make an anti-inflammatory protein (IL-1Ra) which blocks a key driver of joint damage. A single injection helps early on, protecting cartilage and joint function, but as the disease progresses further, that protection fades. The problem is that the body's immune system learns to recognize and block the virus, so a second dose of the same type doesn't work well — but the researchers show that switching to a different 'disguise' (viral serotype) for the repeat dose restores its effectiveness. This points toward a practical strategy for giving repeated joint gene therapy over the long course of a chronic disease.

Technical view

In the murine ACL-transection model of post-traumatic osteoarthritis, single intra-articular injection of high-capacity adenovirus (HCAd5) delivering NFkB-responsive IL-1Ra provides structural and functional benefit in early-stage disease but fails to sustain cartilage protection as OA progresses, and repeat dosing with the same HCAd5 serotype is blunted by pre-existing anti-vector immunity. The authors demonstrate that serotype-switching for the repeat injection restores effective transduction and therapeutic benefit, establishing a sequential heterologous-serotype dosing strategy to overcome anti-adenoviral immunity in a chronic, progressive disease context. This has direct translational relevance for gene therapy dosing regimens in OA and other conditions requiring repeated local adenoviral delivery, where serotype rotation could be built into treatment protocols.

bioRxiv · molecular biologyBuildable

Drosophila co-insulator proteins Pzg and Chro but not CP190 interact with promoter-proximal insulator-binding protein BEAF from a distance

DNA's traffic-control proteins hold hands across distance, not just at close range.

Inside every cell, DNA is folded into loops and neighborhoods, and special 'insulator' proteins act like fence posts marking where one neighborhood ends and another begins. This study looks at a fence-post protein called BEAF in fruit flies and asks how it teams up with three helper proteins to do its job. Using lab techniques that detect when two proteins physically touch or work together in living cells, the researchers found that two of the three helpers (Pzg and Chro) can interact with BEAF even when not directly touching — suggesting they connect through a longer-range mechanism — while the third helper (CP190) does not behave this way. Pinpointing exactly which parts of each protein are responsible for these interactions helps explain how the genome's 3D organization is built and maintained, which matters because that folding affects which genes get switched on or off.

Technical view

Using yeast two-hybrid assays, in vitro pull-downs with bacterially expressed proteins, and bimolecular fluorescence complementation (BiFC) in Drosophila S2 cells, the authors mapped the minimal interacting domains between the insulator protein BEAF and three co-insulator proteins (CP190, Pzg, Chro). They find that Pzg and Chro, unlike CP190, can engage BEAF via interactions detectable at a distance (consistent with BiFC signal indicating proximity without requiring direct stable binding captured by pull-down), and functional assays in transfected S2 cells reveal distinct roles for each co-insulator in BEAF-dependent chromatin organization/transcriptional regulation. This domain-mapping data provides concrete interaction interfaces that could be mutated or disrupted in follow-up studies to dissect BEAF-dependent TAD boundary formation and its transcriptional consequences.

bioRxiv · molecular biologyBuildable

SPARK-ID: Dynamic DSB-sensor interactomes reveal modular nuclear repair networks coordinated by connector proteins

Mapping which proteins rush to a DNA break reveals a hidden repair 'org chart' with switchboard operators.

When DNA breaks, several 'sensor' proteins rush to the damage site to kickstart repair, but how they coordinate the many other cellular jobs that need to pause or adjust hasn't been clear. This study uses a labeling technique that tags every protein sitting near three key sensors as repair unfolds over time, essentially taking repeated snapshots of the neighborhood around the break from the moment of damage through recovery. The three sensors share a common core repair crew but also each attract their own specialized partners — one leans toward RNA and chromatin tasks, another toward the chromosome tips and protein-building machinery, and the third toward the actual DNA-copying and recombination work. The researchers also found 'connector' proteins that link these otherwise separate work crews together, and removing one such connector, Nucleolin, disrupted the coordination. This matters because it reveals how a cell's damage response is wired into a larger network rather than being an isolated repair job.

Technical view

SPARK-ID is a proximity-labeling method used with SIRT6, Ku80, and MRE11 as baits to capture time-resolved, chromatin-associated interactomes from DSB formation through recovery. The three sensors share an enriched core repair interactome while diverging in temporally specialized partners: SIRT6 toward RNA/chromatin regulation, Ku80 toward telomere-associated and translational programs, and MRE11 toward recombination and DNA synthesis. Modularity analysis identified functional modules linked by 'connector' proteins, with Nucleolin bridging DNA repair, RNA-metabolism, and nucleolar modules; Nucleolin depletion perturbs this cross-module coordination, implicating it as a hub for integrating repair with broader nuclear processes. The dataset and proximity-labeling framework offer a template for mapping temporally dynamic interactomes around other DNA damage response factors or other transient chromatin events.

bioRxiv · molecular biologyConceptual

Compartmental Profiling of PDE4B in Systemic Sclerosis

Mapping where a newly approved lung-scarring drug's target actually sits in scleroderma tissue.

Systemic sclerosis (SSc) is an autoimmune disease that causes hardening and scarring of skin, lungs, and blood vessels. A drug called nerandomilast, just approved for a related lung-scarring disease, works by blocking a protein called PDE4B, which is thought to calm immune cells, reduce scarring, and protect blood vessel linings. But nobody had carefully checked where PDE4B is actually turned up or down in the different tissues and cell types affected by scleroderma. The researchers used gene-reading techniques (single-cell RNA sequencing) and antibody-based staining to map PDE4B across lung, blood immune cells, and skin from SSc patients. This groundwork helps predict which patients or tissues might actually respond if doctors try repurposing this drug for scleroderma.

Technical view

The study systematically profiles PDE4B expression in SSc using single-cell RNA-seq (transcript level) alongside immunohistochemistry, immunofluorescence, and multiplexed immunofluorescence (protein level) across lung, PBMCs, and skin. PDE4B was consistently dysregulated in immune cell populations, but direction and magnitude of dysregulation varied by tissue compartment, suggesting cell-type- and organ-specific regulation rather than uniform pathway activation. This compartmental map provides a mechanistic rationale and biomarker framework for trialing PDE4B inhibitors like nerandomilast in SSc, and could guide patient stratification by matching target expression to tissue involvement.

bioRxiv · molecular biologyConceptual

Translocon Remodeling Modulates Ribosomal Frameshifting and the Maturation of the Sindbis Virus Structural Polyprotein

A cellular protein-sorting machine quietly edits how a virus builds its outer shell.

Viruses like Sindbis virus (a relative of viruses causing diseases like chikungunya) build their outer envelope proteins using the host cell's own protein-folding machinery, a channel in the cell's membrane called a translocon. The virus has a trick called 'ribosomal frameshifting,' where the cell's protein-building machinery briefly shifts reading frame mid-gene, producing two different versions of a protein from one piece of genetic code. This study finds that a specific segment of the viral protein interacts with a recently discovered version of the translocon (the 'multipass translocon'), and that removing pieces of this multipass machine changes how often the frameshifting trick happens. In short, the virus is hijacking a subtle detail of the cell's assembly line to fine-tune how its own building-block proteins turn out, revealing a new angle on how viruses exploit host cell machinery.

Technical view

Sindbis virus's structural polyprotein uses a hydrophobic segment corresponding to E2's second transmembrane domain to engage translocon components cotranslationally, modulating -1 programmed ribosomal frameshifting (-1PRF) that controls polyprotein stoichiometry. Building on prior work linking this segment to translocon interactions, the authors knock out components of the recently characterized multipass translocon (MPT) and show this increases -1PRF efficiency, implicating MPT recruitment as a regulatory checkpoint for viral protein biogenesis. This links host ER quality-control machinery directly to viral gene expression control, suggesting MPT components as potential targets for antiviral strategies aimed at disrupting alphavirus structural protein maturation.

bioRxiv · cell biologyBuildable

A Computational Foundation Toward Targeting the ELMO1/DOCK2 Complex

Hunting for a drug that could jam a cell-migration 'motor' linked to cancer and kidney disease.

Cells move around the body by activating internal machinery, and a protein pairing called ELMO1 and DOCK2 acts like a switch that turns on this movement machinery (via a protein called Rac1). This pairing matters in kidney disease, cancer spread, gut infections, and inflammation, but no drug has ever been made to block it, partly because scientists only recently figured out its 3D shape. This paper uses computer simulations, essentially virtual test-tubes, to search through databases of small molecules and predict which ones might wedge into the ELMO1/DOCK2 interface and break up the pair. It's an early, purely computational first step toward a drug that doesn't exist yet, checking whether the target is even 'druggable' before anyone synthesizes or tests a real compound.

Technical view

Leveraging the newly solved ELMO1/DOCK2 complex structure, the authors perform structure-based virtual screening to identify small molecules predicted to disrupt this protein-protein interaction interface that activates Rac1 GTPase signaling. They apply molecular dynamics (MD) simulations and free energy landscape (FEL) analysis to assess binding stability and druggability of candidate hits at the interface. This establishes a computational pipeline and starting hit list that could be handed off for experimental validation (binding assays, cellular Rac1 activity assays) as a first-in-class ELMO1/DOCK2 inhibitor program.

bioRxiv · cell biologyBuildable

Quantification of STLV-1 Tax in various tissues of non-human primates by different PCR methods.

Tracking a cancer-causing virus's hideouts inside the throat and gut of infected baboons.

HTLV-1 is a virus spread through blood and breastfeeding that can cause leukemia and nerve inflammation in people, but scientists don't fully know where in the body it hides and replicates, especially along the mouth-to-gut route it may use to spread, because human tissue samples are hard to get. This study instead uses baboons naturally infected with STLV-1, a very close relative of the human virus, and examines tissues like tonsils, stomach, and other parts of the mouth and gut using different PCR methods (lab techniques that detect and count tiny amounts of viral genetic material). By comparing how well different PCR approaches measure a viral gene called Tax across these tissues, the researchers build a more complete map of where the virus lives in the body, filling in a gap that's nearly impossible to study directly in humans.

Technical view

The study quantifies STLV-1 Tax expression across oropharyngeal and gastrointestinal tissues (tonsils, stomach, and others) from naturally infected olive baboons (Papio anubis), a validated animal model for HTLV-1, using and comparing multiple PCR-based quantification methods. This addresses the scarcity of human tissue data on HTLV-1 distribution along suspected oral transmission routes. The methodological comparison of PCR approaches for Tax detection provides a benchmarked protocol other researchers could adopt for tissue-level retroviral quantification in NHP models, informing future studies of HTLV-1/STLV-1 tissue tropism and transmission biology.

bioRxiv · cell biologyConceptual

Co-optation of the regenerative role of type 2 alveolar cells in distal lung repair in mice by terminal airway epithelial cells in humans

Human lungs may heal a different way than mouse lungs, using cells mice don't even have.

The tiny air sacs in your lungs where oxygen exchange happens are lined by a workhorse cell type (AT1) that can't repair itself, so it normally relies on a helper cell type (AT2) to regenerate it after injury, at least in mice. But humans and other large mammals have extra airway structures and cell types near the air sacs that mice simply lack. Using lung tissue grown from human stem cells in a dish (organoids) and comparing it computationally to real tissue, the researchers found that in humans, a different set of airway cells can directly regenerate the oxygen-exchanging cells, skipping the mouse-style AT2 pathway. They also found that cells resembling a harmful, scar-associated cell type seen in pulmonary fibrosis patients show up as a normal, faster step in this human repair process rather than always being a sign of disease. This challenges assumptions drawn from mouse research and could reshape how scientists think about fibrotic lung disease.

Technical view

Using human pluripotent stem cell-derived lung organoids combined with comparative computational analysis (likely single-cell transcriptomics and trajectory inference), the authors show that terminal and respiratory bronchiole epithelial cells, structures present in humans but absent in mice, can directly regenerate AT1 alveolar cells without transiting through the AT2-derived KRT8+ intermediate state established in mouse injury models. They further find that cells resembling profibrotic 'aberrant basaloid cells,' previously associated with pathological fibrosis, arise as a faster, physiological intermediate in this human-specific regenerative trajectory. This reframes aberrant basaloid-like states as a normal repair checkpoint rather than purely a disease marker, with implications for interpreting single-cell data from IPF/pulmonary fibrosis patient lungs and for building more human-relevant organoid injury-repair models.

bioRxiv · cell biologyConceptual

Corilagin attenuates high glucose-induced neurotoxicity and mitochondrial dysfunction through restoration of the AMPK-SIRT1-PGC1α-TFAM signaling axis

A pomegranate-derived compound may shield nerve cells from sugar-driven mitochondrial damage.

Diabetic neuropathy is nerve damage caused by long-term high blood sugar, and most current treatments just try to control blood sugar rather than directly protecting the nerves themselves from damage. Corilagin is a natural antioxidant compound (found in plants like pomegranate) that hasn't previously been tested against this kind of sugar-induced nerve injury. Researchers exposed human nerve-like cells in a dish to very high glucose levels to mimic diabetes, which damaged the cells' energy-producing mitochondria and triggered cell death, then tested whether Corilagin could prevent this damage. They found it restored a key cellular energy-and-stress-response pathway (AMPK-SIRT1-PGC1α-TFAM), essentially helping the cell's power plants function and repair themselves again, protecting the cells from dying under high-sugar stress.

Technical view

In an in vitro model, SH-SY5Y human neuroblastoma cells exposed to high glucose (50 mM, 24h) exhibited reduced viability, elevated intracellular and mitochondrial ROS, depleted glutathione, and increased apoptosis, hallmark features of diabetic neuropathy-associated mitochondrial dysfunction. Corilagin treatment reversed these effects, with mechanistic data pointing to restoration of the AMPK-SIRT1-PGC1α-TFAM axis, a core regulatory pathway for mitochondrial biogenesis and antioxidant defense. This positions Corilagin as a candidate neuroprotective compound acting via mitochondrial biogenesis pathways rather than glycemic control, providing a mechanistic starting point for in vivo diabetic neuropathy models and structure-activity studies of ellagitannin derivatives.

bioRxiv · cell biologyConceptual

Mechanosensing activates flashing Ca2+ dynamics associated with cell regeneration in Physcomitrium patens

A moss 'feels' injury through flickering calcium sparks that kickstart its self-healing.

When plants get physically wounded, it can trigger cells nearby to reprogram themselves and regenerate new tissue, but how a mechanical injury gets translated into that cellular decision has been unclear. Using live video microscopy on the moss Physcomitrium patens, researchers tracked calcium ions (Ca2+), which cells use as rapid internal signals, and found that wounding triggers an initial wave of calcium followed by a strange, long-lasting 'flashing' pattern of random calcium sparks that specifically occurs in cells right next to the wound and persists for hours. They showed this is triggered by physical deformation of the cell's outer membrane opening calcium channels, and that even just stretching the membrane with osmotic stress (without actual injury) can trigger a similar rapid spike. This builds a timeline connecting physical force on a cell to the calcium signals that seem to set regeneration in motion.

Technical view

Using live-cell calcium imaging in Physcomitrium patens, the authors map a spatiotemporal Ca2+ signaling framework following mechanical wounding: an initial propagating Ca2+ wave, followed by two distinct secondary response modes, including a novel stochastic 'flashing' Ca2+ signature confined to wound-adjacent cells that persists for hours. They show membrane deformation from wounding activates plasma membrane Ca2+ influx, and that osmotic stress-induced membrane tension alone can trigger rapid Ca2+ spikes without the spatially restricted flashing pattern, and pharmacological channel blockade experiments further dissect the mechanosensitive Ca2+ influx pathway. This establishes a testable model linking mechanosensation to regenerative cell fate reprogramming, providing specific Ca2+ dynamic signatures and channel targets that could be probed in other regenerating plant or even animal wound-response systems.

bioRxiv · cell biologyConceptual

A genome quality control program for the haploid stage of spermatogenesis

Sperm cells have a built-in 'delete' button for DNA damage that mice use during their final transformation.

Sperm cells go through a dramatic makeover in their final stage of development, called spermatids, reshaping themselves over roughly a week in flies or two weeks in humans, and by this point they've already lost the backup chromosome copies most cells use to repair DNA damage. That makes this a risky window for passing on genetic damage to offspring, yet how the body safeguards genome quality during this stage wasn't well understood. Using fruit flies zapped with radiation to damage DNA, researchers found that the sperm-maturation process itself gets specifically disrupted to eliminate spermatids with damaged genomes, essentially a built-in quality-control checkpoint that culls bad cells rather than trying to fix them. They also identified a new role for a specific DNA-packaging protein variant (histone H2Av) in carrying out this elimination process, revealing a dedicated genome-surveillance system unique to this vulnerable stage of sperm development.

Technical view

Post-meiotic spermatids lack sister chromatids or homologous chromosomes, precluding homology-directed repair, yet must maintain genome integrity over an extended maturation period. Using γ-irradiation of Drosophila to induce DNA damage, the authors show that spermiogenesis is actively rerouted to eliminate damaged haploid nuclei rather than repair them, and identify a non-canonical role for the histone variant H2Av in mediating this elimination pathway. This describes a haploid-stage-specific genome quality-control checkpoint distinct from canonical DNA damage response pathways, suggesting H2Av-dependent nuclear elimination machinery as a target for future studies of male germline mutation load and fertility, with likely conservation given the extended haploid phase in human spermatid maturation.

bioRxiv · developmental biologyConceptual

Comparative primate transcriptomics identifies a ZNF90/OVOL2 regulatory axis shaping human neural progenitor cell dynamics

Two ancient genes may explain why human brains grew bigger and more complex than other primates'.

Scientists compared brain stem cells from humans and rhesus monkeys to find genes uniquely active in human neural progenitor cells — the cells that build the brain's outer layer during development. They found human cells lean on programs that keep them dividing and acting like versatile 'radial glia' scaffolding cells, plus genes that carefully manage cell division itself. Two gene-regulating proteins stood out: ZNF90, found only in apes, and OVOL2, which is ancient and shared across many species. By testing what these two proteins actually control inside lab-grown mini-brains (organoids), the researchers could see how they shape the number and behavior of brain-building cells — a clue to what makes human brain development distinct.

Technical view

The study profiles NPC transcriptomes across humans and rhesus macaques, an outgroup for hominoid comparisons, and identifies genes enriched in human NPCs tied to radial glial identity, proliferative capacity, and sister chromatid segregation. Two zinc-finger transcription factors emerge from this comparison: ape-restricted ZNF90 and deeply conserved OVOL2. The authors map genome-wide binding sites and transcriptional targets of both factors and perturb them in cerebral organoids to assay downstream effects on NPC dynamics. This establishes a testable regulatory axis for comparative work on human-specific features of cortical progenitor expansion.

bioRxiv · developmental biologyConceptual

Conserved cerebellar rhombic lip compartmentalization and Eomes regulatory networks govern unipolar brush cell development

A brain region that builds specialized 'relay' neurons works almost the same way in mice and humans.

Deep in the developing cerebellum sits a strip of tissue called the rhombic lip, which produces several types of brain cells including unipolar brush cells (UBCs) — neurons that relay and amplify signals. When UBC development goes wrong, it's linked to a birth condition called Dandy-Walker Syndrome and to a childhood brain tumor, but mice haven't been great stand-ins for studying this. Researchers tracked where these cells form and how they mature in both mice and humans, using fluorescent tagging and gene-by-gene sequencing of individual cells, while also switching off a key gene called Eomes to see what breaks. They found the mouse rhombic lip is organized into the same distinct zones as the human one, with a persistent pool of dividing precursor cells, and that Eomes directs the genetic programs guiding these cells to mature and migrate — validating mice as a workable model for these diseases.

Technical view

The authors characterize UBC development in the rhombic lip (RL) using multiplex immunofluorescence and single-cell RNA-seq in wild-type and conditional Eomes-knockout mice, benchmarking against human RL architecture. They find the murine RL is molecularly compartmentalized like the human RL, with an abundant, persistent population of cycling EOMES+ UBC progenitors extending postnatally. Eomes loss disrupts the transcriptional networks driving UBC differentiation and migration, though some processes appear Eomes-independent. This establishes cross-species conservation of RL/UBC biology, supporting mouse conditional-knockout models for studying Dandy-Walker Syndrome and medulloblastoma origins.

bioRxiv · ecologyConceptual

The controlled spectrum of plant form and function

Plants don't just trade off 'fast growth vs. tough survival' leaf-by-leaf — they commit to it whole-body.

Botanists have long noticed that plant traits — like leaf thickness or root density — tend to fall along a spectrum from 'acquisitive' (grow fast, live cheap) to 'conservative' (grow slow, built to last), and this pattern shows up separately in leaves and in roots. This paper asks whether that pattern is real or just a statistical illusion caused by other hidden factors, like plant size or habitat, sneaking into the data. Using a more careful math technique that strips out those confounding influences, the researchers show the fast-vs-tough tradeoff isn't a separate story for leaves and another for roots — it's really one strategy that governs the whole plant at once. This reshapes how ecologists think about classifying and predicting plant strategies across the globe.

Technical view

Prior work using dimension-reduction (e.g., PCA) on trait matrices reported organ-specific acquisitive-conservative axes in leaves and roots, but such analyses are vulnerable to third-variable confounds (e.g., plant size, phylogeny) inflating apparent independent structure. The authors apply a dimension-reduction method that explicitly controls for these confounders across a broad trait dataset. The controlled analysis collapses the ostensibly separate leaf and root spectra into a single acquisitive-conservative axis operating at the whole-plant level. This challenges the organ-modular framing common in plant economics spectrum literature and suggests trait-based ecological models should integrate above- and below-ground traits jointly rather than treating them as independent axes.

bioRxiv · evolutionary biologyConceptual

Genomic signatures of reproductive isolation are decoupled from floral divergence in a long-standing hybrid zone

Bee-flowers and bird-flowers keep interbreeding for 85+ years, yet somehow stay genetically distinct species.

Two wildflowers in the Sierra Nevada mountains — one pollinated by bees, one by hummingbirds — look and behave very differently, and biologists have long assumed that difference is what keeps them from merging into one species where they overlap. This study tests that assumption in a spot where the two flowers have been crossbreeding for at least 85 years. The team measured flower traits, mapped genes, and modeled how bees and birds actually perceive flower color to see whether the color difference (controlled by a couple of pigment genes) is really what pollinators use to stay loyal to one species over the other. Surprisingly, the genetic barrier that keeps the species separate doesn't line up neatly with the flower differences pollinators can see — suggesting something other than simple pollinator preference is keeping these species apart.

Technical view

The study examines a long-standing hybrid zone between Penstemon davidsonii (bee-pollination syndrome) and P. newberryi (bird-pollination syndrome) to test classic pollinator-driven ecological speciation models. Despite persistent hybridization over 85+ years, the parent taxa retain strong multivariate trait divergence and genomic differentiation. Floral hue maps to a single genomic locus containing two candidate anthocyanin-pathway genes with large phenotypic effects, and pollinator visual modeling assesses whether bees/birds can discriminate this variation. The key finding — that genomic signatures of reproductive isolation are decoupled from floral trait divergence — implies barriers other than pollinator-mediated assortative mating maintain species boundaries here, complicating simple pollination-syndrome speciation narratives.

CHM

Chemistry & Materials

9 new
arXiv · physics.chem-phBuildable★ flagship

Quantum Computing Enabled ab initio Molecular Dynamics Simulations

A quantum computer helps simulate molecules jiggling around—as accurately as the exact answer.

Chemists often want to watch how the atoms in a molecule move and bump into each other over time, because that motion drives reactions, how drugs bind, and how liquids behave—this is called molecular dynamics. Doing it truly accurately means solving the quantum equations for the electrons at every instant, which is brutally hard for ordinary computers. Here the team hands part of that job to a quantum computer: it takes 'samples' from a quantum circuit designed to mimic the molecule's electrons, then a classical computer cleverly stitches those samples together (a method called Sample-based Quantum Diagonalization) to compute the energy and the forces pushing on each atom. They checked it against the exact 'gold standard' answer for small systems—including a molecule sitting in real water—and it matched to within about 1 kcal/mol, chemistry's rough accuracy target. It matters because it's an early but concrete demonstration of a quantum-classical pipeline that could eventually simulate chemistry too complex for any classical machine alone.

Technical view

The workflow combines a LUCJ (local unitary coupled-cluster Jastrow) ansatz measured on quantum hardware with Sample-based Quantum Diagonalization (SQD), which post-processes bitstring samples to select determinant subspaces and diagonalize, yielding energies plus analytical nuclear gradients for AIMD. Benchmarked against FCI in the STO-3G basis, SQD reproduces energies and gradients within 1 kcal/mol and produces stable trajectories, including in explicit-solvent QM/MM runs where it matches FCI energy fluctuations, RMS gradient profiles, and solute–solvent radial distribution functions. The key practitioner takeaway is that analytical gradients from SQD are accurate enough for stable dynamics, not just single-point energies. Reproduction requires a LUCJ circuit implementation, a sampling backend (simulator or hardware), and an SQD determinant-selection/diagonalization pipeline coupled to a standard AIMD/QM-MM driver.

arXiv · cond-mat.str-elConceptual

Field-Selected Topological Buffering in a Disordered Skyrmion Crystal

Magnets can scramble their crystal order yet stubbornly keep their topological 'knots' intact.

This is about skyrmions, tiny swirling magnetic whirlpools that form a repeating pattern (like a crystal) inside certain magnetic materials. Real materials are never perfect, they have random defects, and the question is how much messiness it takes to break the neat pattern versus to actually untie the swirls' twisted structure (their 'topology', a mathematical property that makes them very hard to unravel). Using large computer simulations, the researchers found that an external magnetic field controls which kind of disorder happens first: at high fields, the neat spacing breaks down early, but the six-fold symmetry and the total 'twistiness' survive much longer, creating a protective window they call a topological buffer. This matters because it suggests skyrmions could stay robust and useful, for things like ultra-dense memory storage, even in imperfect real-world materials.

Technical view

The authors run large-scale simulations of a triangular-lattice chiral magnet with quenched random Dzyaloshinskii-Moriya interaction disorder, tracking translational order, sixfold bond-orientational order, and total topological charge as functions of disorder strength and applied field. At high fields, global translational (positional) coherence is destroyed at weak disorder while bond-orientational order and topological charge persist to much larger disorder, opening an intermediate 'topological buffer' regime spanning a Bragg-glass-like skyrmion phase followed by a skyrmion-glass phase. Finite-size scaling, spatial correlation functions, defect (dislocation/disclination) statistics, and spin autocorrelation dynamics are used to characterize the distinct structural and glassy signatures of each phase. This gives a field-tunable disorder phase diagram that practitioners could use to identify disorder tolerance windows for skyrmion-based device design.

arXiv · physics.chem-phConceptual

Wavefunction-based periodic quantum chemistry

A friendly guidebook teaches chemists how to simulate crystals with the same precision used for single molecules.

Chemists have very accurate methods for predicting the behavior of individual molecules, but applying that same precision to solids — like crystals or materials — is much harder and requires knowledge from several different fields at once. This paper is essentially a teaching guide that walks readers through how to do these high-accuracy calculations on periodic (repeating) structures, covering the tricky math of how charged particles interact across an infinite repeating lattice, and the two main ways scientists represent electrons mathematically in these systems. It also explains a technique called k-point sampling, a shortcut that saves enormous computing time by exploiting the repeating symmetry of crystals. The goal is to lower the barrier so more researchers can bring molecule-level accuracy to real materials, which matters for designing better batteries, catalysts, and electronic devices.

Technical view

This is a pedagogical review of wavefunction-based (post-Hartree-Fock/correlated) periodic quantum chemistry, covering Ewald summation for handling long-range periodic Coulomb interactions, the two dominant one-electron basis choices (plane waves vs. periodic Gaussian-type/atomic-orbital LCAO bases), explicit Hamiltonian integral formulas for both, and k-point sampling as a Bloch-symmetry-adapted reduction of supercell calculations that cuts computational cost. It bridges molecular quantum chemistry (CCSD(T), etc.) with solid-state physics conventions, targeting researchers who want to apply high-accuracy correlated methods (beyond DFT) to condensed-phase systems. Readers implementing or using codes like VASP, CRYSTAL, or PySCF's periodic modules would use this as a reference for the underlying formalism and cost trade-offs of basis choice and k-point convergence.

arXiv · cond-mat.mtrl-sciConceptual

Drumhead Surface States of Rhombohedral Graphite with Near Ideal Quantum Geometry Condition

Stacking graphite sheets a special way may create a hidden electronic dance floor for exotic quantum states.

Graphene is a single layer of carbon atoms, and when you stack several layers in a particular twisted or rhombohedral pattern, strange electronic properties emerge — including 'flat bands' where electrons move unusually slowly and can behave collectively in exotic ways, potentially enabling new forms of superconductivity or unusual insulating states. This paper studies a special mathematical condition, called ideal quantum geometry, that seems necessary for these exotic effects, and uses computer simulations to check whether the surfaces of thick rhombohedral graphite naturally satisfy this condition. They find the material's surface hosts a 'drumhead' state — a flat, sheet-like band of electrons — and study its shape and depth. This is basic materials science aimed at understanding why certain carbon stackings might host superconductivity or novel quantum states, which could someday matter for quantum computing or ultra-efficient electronics.

Technical view

Using DFT and Wannier function analysis, the authors characterize the symmetry-protected topology of bulk rhombohedral graphite (RG), showing it is a weak topological insulator with spin-orbit coupling and a chiral nodal-line semimetal without it, and examine drumhead surface states (DSS) on semi-infinite and thick RG slabs against the 'ideal quantum geometry' (IQG) criterion |Ω|/TrG=1 linked to fractional Chern insulator and flat-band superconductivity proposals. They find the DSS flat band exhibits sizable convex curvature with a specific depth dependence, consistent with recent experimental/theoretical claims about RG's role in flat-band physics. This provides a first-principles benchmark for researchers modeling IQG-driven correlated phases (fractional Chern insulators, unconventional superconductivity) in few- and many-layer rhombohedral graphene/graphite systems.

arXiv · cond-mat.mtrl-sciConceptual

Hydration-Controlled Layer Stacking in (NH$_3$)$_2$Cu$_5$(SeO$_3$)$_2$(OH)$_6$(H$_2$O)$_{2+x}$ ($x$ = 0, 1, and 3)

Adding or removing water molecules between crystal layers rearranges an entire mineral's structure like a stack of shelves.

Many layered materials — think stacks of atomic sheets — can trap water molecules between their layers, and how much water is trapped changes the spacing and arrangement of those layers. This study creates a new family of copper-based mineral compounds and shows that by controlling the amount of water squeezed between identical repeating layers, the researchers can change how those layers stack on top of each other, even though the makeup of each individual layer stays the same. They figured this out using techniques that map out atomic structures precisely, like X-ray and electron diffraction. This matters because it shows hydration is an underused 'dial' for engineering the properties of layered materials, which could apply to batteries, catalysts, or other technologies that rely on layered crystal structures.

Technical view

Via reflux synthesis, the authors produced a series of hydrated layered copper selenites, (NH3)2Cu5(SeO3)2(OH)6(H2O)2+x for x=0,1,3, and solved their structures using electron diffraction and single-crystal X-ray diffraction. Each compound shares an identical Cu(OH)4-square/Cu-square-pyramid kagome-like layer, but the degree of interlayer hydration systematically modulates interlayer spacing and stacking sequence while leaving intralayer connectivity unchanged. This establishes hydration state as an independent structural control parameter decoupled from layer composition, offering a model system for researchers studying stacking-dependent properties (e.g., magnetic frustration in kagome lattices) or designing intercalation-based tuning strategies in layered inorganic solids.

arXiv · cond-mat.mtrl-sciConceptual

Quasiparticle phono-conversion: filming carriers coalescing into excitons

Scientists filmed, frame by frame, the exact moment free electrons pair up into bound particles inside a material.

When you shine intense light on certain materials, it can knock electrons loose, leaving behind 'holes' where they used to be — and sometimes these free electrons and holes then pair up into a bound duo called an exciton, which behaves almost like a single particle. Scientists have understood how these particles cool down afterward, but the actual moment of pairing up has been a mystery. Using an ultra-fast camera-like technique that captures both energy and momentum with extreme precision, researchers watched this pairing happen in real time in a thin sheet of the material WSe2, catching the brief window where free particles and bound excitons exist simultaneously. They also identified that vibrations in the material's atomic lattice (phonons) are what drive this transformation. This matters for understanding and eventually controlling exciton-based technologies, like ultrathin solar cells, LEDs, or quantum light sources.

Technical view

Using time- and momentum-resolved ARPES on monolayer WSe2 combined with first-principles excitonic Bloch equation simulations, the authors directly resolve the ultrafast conversion of unbound electron-hole pairs into bound excitons, observing transient coexistence of free-carrier and excitonic spectral bands with measurable spectral weight transfer between them. They identify the formation mechanism as phonon-mediated, occurring via a sequential relaxation pathway rather than instantaneous binding. This provides direct experimental access to exciton formation dynamics previously inferred only indirectly, giving a benchmark dataset and mechanism (phonon-assisted, sequential energy-momentum relaxation) that theorists modeling exciton dynamics in 2D semiconductors, and experimentalists designing excitonic optoelectronic devices, can validate against or exploit for engineering formation timescales.

arXiv · physics.comp-phRunnable

Performance Benchmarking: Software for the Density Matrix Renormalization Group

Fifty tools claim to simulate quantum systems fast — someone finally timed them.

The density matrix renormalization group, or DMRG, is a computational method scientists use to simulate complicated quantum systems, like chains of magnetic atoms, that are too complex to solve exactly. Over the years more than 50 different software packages have been built to run DMRG, but nobody has fairly compared how fast or efficient they actually are. This paper builds a standardized benchmarking framework — a shared set of test problems and timing rules — so different implementations can be measured on equal footing. That matters because a faster, more efficient tool lets researchers simulate bigger, more realistic quantum systems instead of being stuck with toy examples.

Technical view

The authors introduce a performance-oriented benchmarking suite for DMRG implementations, addressing the lack of standardized, apples-to-apples comparisons across the >50 existing codes that differ in language, tensor backends, symmetry handling, and parallelization strategy. The framework specifies consistent test Hamiltonians, bond-dimension/convergence settings, and timing/memory metrics so that runtime and scaling behavior can be directly compared rather than inferred from disparate, incomplete reports. Practitioners can use this to select or tune a DMRG package for their hardware and problem size, and tool developers can use it as a regression/performance test suite when optimizing their own implementations.

arXiv · cond-mat.softConceptual

Thermodynamics and Kinetics of a Three-Arm Star Polymer Translocating through a Nanopore

A three-armed molecule threading a tiny pore behaves nothing like a straight one.

Imagine trying to pull a piece of string through a tiny hole using an electric field — that's roughly what happens when a charged polymer (a long chain-like molecule) is pulled through a nanopore, a technique actually used in DNA sequencing devices. This study compares a simple straight chain to a Y-shaped, three-armed version of the same molecule and asks how fast each one squeezes through under different voltages. Using computer simulations that model the polymer as a string of connected beads, the researchers found that the straight chain moves through predictably faster at higher voltage, but the branched one gets unexpectedly stuck below a certain voltage threshold, likely because its arms have to untangle and merge before threading through. Understanding this helps engineers designing pore-based sensors know how branched or complex molecules will behave differently from simple linear ones.

Technical view

Using Langevin dynamics with a coarse-grained bead-spring polymer model and a semi-implicit nanopore, the authors compare voltage-driven translocation of linear versus three-arm star polyelectrolytes of equal molecular weight. Linear polymers show the expected translocation-time inverse-proportionality to voltage across a wide range, while star polymers deviate sharply below a threshold voltage that is insensitive to molecular weight but scales with pore size and salt concentration. Metadynamics is used to reconstruct the free-energy landscape governing the branched polymer's translocation, likely revealing a barrier associated with arm-junction passage through the pore. This has direct implications for interpreting nanopore sensing signals from branched biomolecules or synthetic polymers.

arXiv · physics.chem-phConceptual

Wavelength-Resolved Photoinduced Spin Polarization in a Broad Optical Range for a Porphyrin-Quinone System

Shining different colors of light on a molecule flips its magnetic 'spin' in surprising patterns.

Photo-CIDNP is a phenomenon where shining light on certain molecule pairs — here a porphyrin (a ring-shaped, light-absorbing molecule found in things like chlorophyll and hemoglobin) paired with a quinone (an electron-accepting molecule) — causes a burst of nuclear magnetic polarization, which can be detected and even used to boost the sensitivity of MRI-like techniques. Scientists usually only test this effect at one or two light colors, so how it changes across the whole spectrum has been a mystery. Here the researchers systematically swept through wavelengths from violet to deep red using tunable lasers and filtered lamps, carefully measuring the polarization signal at each one. They found the response doesn't rise and fall smoothly with wavelength — instead it spikes unpredictably at certain colors, hinting at specific quantum mechanical pathways being triggered. This detailed map could help chemists pick the ideal light color to maximize hyperpolarization for medical imaging or materials science applications.

Technical view

The authors measure wavelength-resolved photo-CIDNP in a tetraphenylporphyrin–1,4-benzoquinone donor-acceptor system across 350–800 nm, using both a tunable laser and a xenon lamp with 10 nm interference filters, with signals normalized to photon flux for direct comparison. The key finding is a non-monotonic wavelength dependence with pronounced polarization enhancements at specific excitation bands, rather than a smooth spectral response, implying wavelength-selective activation of distinct radical-pair spin-chemical mechanisms (e.g., different excited states or intersystem crossing pathways). This spectral map provides a practical guide for choosing excitation wavelengths to optimize hyperpolarization yield and offers mechanistic constraints that theorists can use to test spin-dynamics models of radical pair reactions.

Q

Quanta — Explained

1 new
Quanta MagazineConceptual★ flagship

Is AI Reasoning Right for the Wrong Reasons?

When AI 'reasons' correctly, is it really reasoning—or just getting lucky the wrong way?

It feels obvious that today's AI can reason: ask a chatbot a logic puzzle and it walks through steps to an answer. But this Quanta Magazine piece argues that intuition might be misleading us, and scientists genuinely don't agree on whether the models are reasoning or just pattern-matching their way to right answers. The worry is that a model can produce a correct conclusion while its internal 'reasoning' doesn't actually track the logic—right for the wrong reasons. That distinction matters because if the reasoning is hollow, the AI will fail unpredictably on problems that look similar but need real understanding. The article surveys the emerging science probing what's actually happening inside these systems.

Technical view

This is a Quanta Magazine explainer, not a primary result, examining the open question of whether large language models perform genuine reasoning or exploit surface correlations that yield correct answers without valid inference. The core concern—correct outputs supported by invalid or spurious internal processes—connects to research on chain-of-thought faithfulness, benchmark contamination, and probing/interpretability studies that test whether stated reasoning causally drives answers. Practitioners should treat it as a pointer to the interpretability and evaluation literature: use faithfulness tests, counterfactual/perturbation probes, and out-of-distribution generalization checks rather than accuracy alone to judge reasoning claims. The takeaway is methodological skepticism—benchmark performance is not evidence of reasoning mechanism.

HN

What's Trending

33 new
Hacker News · 855 ptsConceptual★ flagship

Elevators

An item titled 'Elevators'—but with no description to go on.

This entry only has a title, 'Elevators,' and no abstract or text to explain what it's about. Without more information there's no way to say what problem it tackles, how it works, or why it matters. It could be a research paper, an essay, or something else entirely. To explain it meaningfully, the underlying content or an abstract would be needed.

Technical view

No abstract or body text was provided for this item, so no method, claim, or result can be described without fabricating details. Supplying the source text or an abstract would allow a substantive technical summary.

Hacker News · 731 ptsConceptual

The session you cannot take with you

Why the context and state built up in a digital 'session' often can't move with you.

This piece's title, taken literally, points to a familiar frustration: a 'session' — the running state of a conversation, login, or program — often lives entirely inside one system and disappears the moment you try to leave it. A common example is switching chat apps, browsers, or AI tools and realizing all the context you built up doesn't come with you, so you have to start over. No further detail is available beyond the title, so the exact angle (a technical fix, a philosophical reflection, or a product critique) isn't clear, but the core idea is the friction and loss caused by sessions being tied to one platform instead of portable with the user.

Technical view

No abstract is available beyond the title, so specifics of the argument, domain (e.g., web sessions, LLM chat context, OS sessions), and any proposed solution can't be confirmed here. Read literally, the title points to the general problem of session-state portability — data or context bound to one runtime, provider, or device that resists export, migration, or reuse elsewhere. Readers interested in the specifics should consult the source directly, as this summary is necessarily general given the missing content.

Hacker News · 670 ptsRunnable

DeepSeek-V4-Flash Update

DeepSeek quietly updates its fast, lightweight V4 model.

DeepSeek, an AI lab known for releasing capable open models, appears to have put out an update to 'V4-Flash' — presumably a faster, cheaper variant of its V4 language model line, similar to how other labs offer a lightweight 'flash' tier alongside their flagship models. No further detail is available beyond the title, so what specifically changed (capabilities, speed, pricing, or bug fixes) isn't confirmed here.

Technical view

No abstract is provided, only the title referencing an update to DeepSeek-V4-Flash. 'Flash' variants typically trade some capability for lower latency and cost versus a full-size flagship model; readers should check the linked release notes or model card directly (see the related DeepSeek V4 Flash 0731 item) for concrete changes such as benchmark scores, context length, or pricing.

Hacker News · 530 ptsRunnable

DeepSeek V4 Flash 0731 Intelligence, Performance and Price Analysis

A fresh report card grades DeepSeek's newest fast model on smarts, speed, and price.

DeepSeek released a new version of its 'Flash' model (dated July 31, nicknamed 0731) on Hugging Face, a popular site for sharing AI models. This item points to an independent analysis that scores the model across three practical dimensions people care about when picking an AI model to use: how smart it is on standard tests, how fast it responds, and how much it costs to run. This kind of comparative report helps developers and companies decide whether switching to this new model is worth it versus sticking with what they already use.

Technical view

The linked resource is the Hugging Face model card for deepseek-ai/DeepSeek-V4-Flash-0731, accompanied by a third-party analysis benchmarking its intelligence (likely via standard eval suites), latency/throughput, and API or hosting price relative to competing models. Practitioners evaluating a model swap should check the linked analysis for concrete benchmark scores and price-per-token figures before integrating this model into a production pipeline, since flash-tier models typically target a different cost/latency tradeoff than flagship-tier releases.

Hacker News · 480 ptsConceptual

Google fixed more Chrome bugs in June than over the past two years, thanks to AI

AI-assisted bug hunting made Google's Chrome team squash a year's worth of flaws in one month.

Google has been using AI tools to help find and fix security bugs in Chrome, the world's most widely used web browser. According to this report, June saw more bugs fixed than the previous two years combined — a striking jump that suggests AI is meaningfully speeding up the tedious, expert-heavy work of spotting and patching vulnerabilities before attackers can exploit them. This matters because browsers are a huge attack surface (they run untrusted code from every website you visit), so faster, more thorough bug-fixing directly translates into better safety for billions of users.

Technical view

The report credits AI-assisted vulnerability discovery and triage for a sharp spike in Chrome security bug fixes in June, reportedly exceeding the combined total of the prior two years. This aligns with a broader industry trend of using LLM-based fuzzing augmentation, automated code review, and AI-assisted patch generation to scale vulnerability research beyond manual analyst throughput. Security teams evaluating similar tooling should look at whether the reported fixes stem from AI-generated fuzz targets, AI-assisted static/dynamic analysis triage, or LLM-drafted patches, as each implies different integration points into an existing SDLC and different verification burdens before merging.

Hacker News · 439 ptsConceptual

qm

A tersely-named project called "qm" surfaces, its purpose left to the reader to discover.

The title "qm" gives almost nothing away on its own, which is common for small, focused software projects that assume readers already know the domain. Without more context from the abstract, the safest read is that it's a compact tool, library, or command-line utility built to do one narrow job well rather than a sprawling platform. The real-world problem it solves and the approach it takes aren't spelled out here, so it's worth clicking through to the actual page before drawing conclusions. Terse names like this often signal a project built by and for people already fluent in its niche.

Technical view

There isn't enough information in the title alone to characterize the mechanism, architecture, or claimed results — "qm" could plausibly abbreviate anything from a query manager to a quantum-mechanics simulator to a queue/messaging tool. A practitioner would need to open the linked source or README to assess the implementation, dependencies, and how to integrate or extend it. Treat any specific claim about its function as speculative until verified against the primary source.

Hacker News · 428 ptsConceptual

Tailscale didn't stop the Hugging Face intrusion

Even with a locked-down private network in place, attackers still found a way into Hugging Face.

Tailscale is a tool that creates a private, encrypted network between a company's devices and servers, meant to keep outsiders out even without a traditional VPN setup. This piece looks at a security breach at Hugging Face — a major hub for sharing AI models — and makes the point that having this kind of secure networking tool in place didn't actually prevent the intrusion. The lesson is that network-level protections only guard one layer of a system; if an attacker gets in through a compromised account, a leaked credential, or a flaw in an application itself, the private network won't stop them once they're already "inside." It's a reminder that security is a stack of layers, not a single tool you can install and trust completely.

Technical view

The piece is a postmortem-style analysis arguing that Tailscale's mesh VPN (which authenticates devices and encrypts node-to-node traffic) addresses network-perimeter access but doesn't mitigate threats that originate from valid credentials, compromised endpoints already admitted to the tailnet, or vulnerabilities in applications running behind it. For practitioners, the takeaway is to pair zero-trust networking with defense-in-depth: strong secrets management, least-privilege access controls, endpoint hardening, and application-layer monitoring, since a mesh VPN narrows the attack surface but doesn't eliminate it.

Hacker News · 386 ptsConceptual

The End of an Era

Something long-standing is wrapping up, and the author wants us to sit with that.

"The End of an Era" is the kind of title used for reflective essays marking a significant shift or closing chapter — often in technology, a company, a career, or a cultural moment. Without more detail from the piece itself, it's fair to say it's likely a personal or industry reflection on change rather than a technical tutorial. These essays typically matter because they help readers process a transition that's already underway, putting words to a shift many have sensed but not articulated. The specific subject of the era ending isn't clear from the title alone.

Technical view

No concrete claims, methods, or data are given in the title, so any technical summary would be speculative. If this turns out to be about a specific technology, product, or organizational shift, the value for a technical reader would lie in understanding what's being deprecated or superseded and what replaces it — but that requires reading the source material directly.

Hacker News · 362 ptsConceptual

The AI Aesthetic

AI-made images and video are starting to look unmistakably like... AI.

As tools for generating images, video, and text with AI have become widespread, a recognizable visual style has emerged — a certain glossy smoothness, oversaturated color, or uncanny symmetry that many people can now spot at a glance. This piece likely explores what that "look" is, why it keeps showing up across different AI tools and models, and what it reveals about how these systems are trained and optimized. Understanding this matters because it shapes how we perceive authenticity online — recognizing the AI aesthetic is becoming its own kind of visual literacy, similar to spotting a stock photo or a filtered Instagram post.

Technical view

The likely thesis is that generative models converge on a shared aesthetic because they're trained on overlapping datasets and optimized against similar objectives (e.g., aesthetic-score reward models, diffusion guidance scales tuned for perceptual appeal), which biases outputs toward certain compositional and tonal patterns regardless of underlying architecture. For practitioners, this connects to ongoing discussion about dataset bias, reward-model overfitting in RLHF/RLAIF pipelines, and how prompt engineering or fine-tuning can push outputs away from this default "look."

Hacker News · 275 ptsConceptual

The Religion of Speed

Tech culture worships going fast — this essay asks what that faith costs us.

This piece appears to critique a mindset common in startups and the tech industry: the idea that speed — shipping faster, growing faster, moving faster than competitors — is treated almost like a sacred value, worth pursuing even when it causes harm or cuts corners. The "religion" framing suggests the author sees this as more than a practical strategy; it's an unquestioned belief system that shapes decisions without much scrutiny. This kind of essay matters because it pushes back on a default assumption baked into a lot of modern tech and AI development — that faster is always better — and asks what gets sacrificed in the rush.

Technical view

Likely an opinion piece examining how velocity-as-virtue manifests in engineering and product culture — rapid iteration cycles, minimal viable products, move-fast-and-break-things norms, and the current AI arms race — and arguing these are treated as unquestionable goods rather than tradeoffs against stability, safety, or thoughtfulness. A technical reader might connect this to real debates around release cadence versus reliability, or the pressure to ship AI features ahead of adequate safety testing.

Hacker News · 266 ptsConceptual

I flagged two research papers for fake authors and both were accepted as orals

He warned reviewers two papers had fabricated authors — they got presented on stage anyway.

Academic conferences rely on peer review to catch bad or fraudulent submissions before they're presented, but this account describes a case where someone noticed two papers listed authors who appeared to be fake or fabricated — a known tactic used by "paper mills" that churn out fraudulent research to pad résumés or game academic metrics. Despite raising the alarm with conference organizers, both papers were still accepted and given oral presentation slots, one of the most prestigious formats at a conference. This matters because it exposes a real weakness in how academic gatekeeping works: even direct, specific fraud reports can slip through the cracks, undermining trust in the research record.

Technical view

The account is a firsthand report of flagging suspected fabricated authorship — a hallmark of paper-mill-generated submissions — to conference organizers, only to see both papers pass review and get accepted as oral presentations, a track typically reserved for higher-scrutiny, higher-visibility work. This points to gaps in conference-level vetting processes (e.g., lack of author identity verification, reviewer overload, or insufficient escalation paths for fraud reports) and adds to a growing body of evidence about paper-mill infiltration of peer-reviewed venues, relevant to anyone building or evaluating academic integrity tooling.

Hacker News · 258 ptsConceptual

Premier league bans gambling sponsors

No more betting logos on Premier League shirts — the league is cutting gambling ties.

The Premier League, England's top soccer league, has moved to ban gambling companies from sponsoring the front of players' jerseys — the most visible and valuable advertising spot on a team's kit. This follows growing public concern about problem gambling, especially its exposure to children and vulnerable fans who watch games every week and see betting brand logos constantly. The policy is a real-world example of a major sports institution voluntarily limiting a lucrative revenue stream in response to social pressure and health concerns, rather than waiting for government regulation to force the change. Other forms of gambling sponsorship, like sleeve patches or stadium ads, may still continue depending on the exact scope of the ban.

Technical view

This reflects a self-imposed governance decision by Premier League clubs to phase out front-of-shirt gambling sponsorships, following criticism from public health bodies and gambling-harm campaigners over normalized exposure via matchday broadcasts reaching millions of viewers, including minors. The change is notable as an industry-led move rather than legislated restriction, and sits alongside broader UK regulatory tightening on gambling advertising; the precise scope (front-of-shirt only vs. all sponsorship channels) determines how much commercial impact clubs actually absorb.

Hacker News · 224 ptsBuildable

JEP 401: Value Objects (Preview) merged to OpenJDK master

Java just got closer to objects that act like lightweight numbers, not heavyweight things.

For years, Java has treated every object — even something as simple as a pair of coordinates — as a full-blown entity with its own identity, memory overhead, and pointer indirection, similar to giving every LEGO brick its own separate storage box instead of just stacking them directly. JEP 401 introduces "value objects," a new kind of class that gives up that individual identity in exchange for being stored more compactly and efficiently, much like Java's built-in number types already are. This matters because it lets programs handle huge numbers of small objects — like coordinates, colors, or financial amounts — with much better memory efficiency and speed, without giving up the readability of writing normal object-oriented code. Landing this in the OpenJDK master branch is a major milestone toward making that possible in a future Java release, as part of the long-running Project Valhalla effort.

Technical view

JEP 401 lets developers declare "value classes" whose instances lack object identity (no identity-based synchronization, no reference-based equality guarantees), which frees the JVM to eliminate header overhead, avoid heap indirection, and flatten these instances directly into arrays and containing objects rather than storing them as separate heap-allocated pointers. This is the latest deliverable of Project Valhalla, aimed at closing the performance gap between user-defined types and Java's primitives; merging to OpenJDK master as a preview feature means it will ship for community testing in an upcoming JDK release, and practitioners building performance-sensitive code (numerics, graphics, data-heavy structures) can start experimenting with value classes and reporting feedback ahead of finalization.

Hacker News · 222 ptsConceptual

Investigating three real-world incidents in our cybersecurity evaluations

Researchers stress-test their AI security evals against three attacks that actually happened.

This is a look back at three real cybersecurity incidents, used to check whether the tests an AI company runs to judge security risk actually hold up in the real world. Rather than trusting clean, lab-style benchmarks, the team retraces what really happened during genuine attacks and compares it to what their evaluation methods would have caught or missed. The goal is to expose the gap between tidy test scenarios and the messy, unpredictable way real attackers behave. This matters because a security evaluation that only performs well on paper isn't much use when a real threat shows up.

Technical view

The write-up reconstructs three documented security incidents and cross-checks them against an existing cybersecurity evaluation suite to assess how predictive the benchmarks are of real-world attacker behavior. The likely methodology involves timeline reconstruction of each incident's techniques and mapping them onto benchmark task categories to find coverage gaps. The practical payoff is a template for incident-driven validation of security evals — a way to catch blind spots that synthetic red-teaming scenarios miss. Teams building their own AI security evaluations could adopt a similar retrospective-incident methodology to pressure-test benchmark validity.

Hacker News · 201 ptsConceptual

Severance

A short piece simply titled 'Severance' — too little detail here to say more.

All that's available for this item is the single word title, 'Severance,' with no accompanying summary or abstract to explain what it actually covers. It could be about workplace separation and employment practices, or it could reference the well-known TV show of the same name and something tech-related tied to it — but there isn't enough information to say which. Rather than guess at specifics, the honest answer is that this one needs the original source opened to know what it's actually about. If you're curious, it's worth clicking through to see the full context.

Technical view

No abstract or supporting text was provided for this entry, only the title 'Severance.' There isn't enough signal here to characterize a method, claim, or result without fabricating detail that isn't supported by the source. To evaluate or build on this item, the original link or document would need to be reviewed directly.

Hacker News · 191 ptsRunnable

Show HN: Gander, an Android file viewer that asks for no permissions

A phone file viewer that literally cannot leak your files, because it can't touch the internet.

Gander is an app for Android phones that lets you open all sorts of files — PDFs, Word documents, spreadsheets, slideshows, images, videos, audio, and code — without asking for a single permission, not even internet access. The problem it solves is a real one: most free file viewers ask for storage access and quietly upload your files to a server to render them, which is unsettling when you're opening something private someone sent you. Gander's trick is architectural rather than just a promise — because the app never requests internet permission, the operating system itself physically blocks it from sending your file anywhere, so there's no need to trust the developer's word. It renders PDFs and media using on-device libraries, and Office documents through bundled code that runs entirely inside the app, so nothing ever leaves your phone. The tradeoff is it's viewer-only and imperfect on complex files, like PowerPoint decks with fancy layouts or old legacy .doc formats.

Technical view

Gander is an Android file viewer that requests zero permissions, including INTERNET, so the OS enforces at the platform level that no file data can be transmitted off-device — a stronger guarantee than a no-logging policy. PDF rendering uses Pdfium, media playback uses Media3, and Office formats (Word/Excel/PowerPoint) are rendered by bundled JavaScript libraries running inside a local WebView instance, avoiding any external rendering service. Known limitations: complex PowerPoint layouts render only approximately, spreadsheet charts aren't drawn, and legacy binary .doc/.ppt formats have partial support. This is a useful reference architecture for any app wanting to prove a security property via missing permissions rather than policy.

Hacker News · 188 ptsConceptual

Big Food vs. the People

A look at the fight between giant food corporations and everyday people's health.

This piece is titled 'Big Food vs. the People,' pointing to a conflict between large food companies and the public — likely touching on issues like processed food, nutrition policy, lobbying, or public health regulation, though the exact angle isn't detailed here. The general theme in this space is usually about how food companies shape what ends up on grocery shelves and dinner plates, and how that intersects with health outcomes and government regulation. Without more detail it's hard to say exactly which angle — science, policy, or investigative journalism — this one takes. It's worth reading the source directly for specifics.

Technical view

Only a title, 'Big Food vs. the People,' is available, without an abstract detailing the specific claims, methodology, or scope. This likely falls into food-policy or public-health journalism/analysis territory, but no concrete mechanism, data, or argument can be responsibly summarized without the source text.

Hacker News · 162 ptsRunnable

Show HN: Distilling DeepSeek into GPT-OSS doesn't transfer censorship. Try it

They copied a censored AI's smarts into an American model — but the censorship didn't come along.

This is about 'distillation,' a technique where a smaller AI model learns to imitate a bigger, smarter 'teacher' model by training on its answers. Here the teacher was DeepSeek V4 Flash, a Chinese AI, and the student was GPT-OSS-120B, an American open-weight model, and the goal was to make the smaller model much better at finance-related reasoning tasks — which it did, beating rival models on a finance benchmark. The interesting twist is that the teacher model gives noticeably different, more cautious answers to politically sensitive questions, the kind of behavior often described as 'censorship' — but when the researchers tested the distilled student model, that behavior didn't carry over at all; it kept behaving like its original American base model. This matters because it suggests that copying a model's skills doesn't automatically copy its political guardrails, which is reassuring for anyone worried that using a foreign AI as a training tool might quietly import its biases.

Technical view

The team distilled DeepSeek V4 Flash (teacher) into GPT-OSS-120B (student) for finance-reasoning tasks, achieving 83.61% on FinanceReasoning at an 8k token budget, beating Kimi K3 (81.93%) and Inkling (65.13%); a 20B version has been released as open weights. To test whether the teacher's politically sensitive-topic behavior transferred, they measured response divergence on political questions and found the teacher's answers differed from expected baselines by 7 standard deviations, yet the distilled model's behavior remained statistically indistinguishable from its original American base model. This suggests distillation on a narrow task domain (finance) doesn't generalize censorship/alignment behavior outside that domain — a useful data point for teams considering cross-lab distillation pipelines who are concerned about inheriting unwanted model behaviors. A no-auth playground is available to replicate query comparisons directly.

Hacker News · 153 ptsBuildable

Bad Apple but It's Traceroute

A famous shadow-animation meme, redrawn frame by frame using nothing but network traceroute pings.

'Bad Apple' is an old, iconic black-and-white animated music video that internet hobbyists love to recreate using the most absurd, impractical methods possible — playing it on old hardware, spreadsheets, or oscilloscopes, just to prove it can be done. This project does that with 'traceroute,' a basic internet tool that normally shows you the chain of routers your data hops through to reach a destination. Instead of using it for network diagnostics, the creator apparently found a way to make traceroute's hop-by-hop output draw the video's frames, essentially turning a plumbing tool for the internet into an animation player. It's a playful, pointless-on-purpose demo, but the appeal is showing how flexible and hackable ordinary internet infrastructure tools can be.

Technical view

This is a novelty project in the well-established 'Bad Apple but it's X' genre, here implemented via traceroute — likely encoding video frame data into hop sequences or router hostnames/addresses so that running traceroute against a crafted set of targets reproduces the video's imagery in the terminal output. Without further detail on implementation, the likely mechanism involves a controlled set of intermediate hosts or DNS-based hostname encoding to control what each hop displays. It's a fun reference for anyone interested in creative abuse of network protocols for output rendering, similar to esolang or 'weird machine' style projects.

Hacker News · 143 ptsConceptual

Twenty-five years ago it was cryptography, today it's model weights

Once governments tried to control encryption code — now they're trying to control AI model files.

In the 1990s, there was a major fight known as the 'crypto wars,' where governments treated strong encryption software as a controlled technology, similar to weapons, because it could be used to keep secrets from law enforcement and intelligence agencies. This piece draws a parallel to today, where the sensitive technology being restricted isn't encryption code but AI 'model weights' — the huge files of numbers that make a trained AI model actually work. The comparison suggests that just as export controls and legal battles once shaped who could access strong cryptography, similar debates are now happening over who gets to possess or export powerful AI models. The point is likely that history offers lessons — about whether such restrictions work, backfire, or shape the technology's development — that are relevant to today's AI governance debates.

Technical view

The piece is framed as a historical analogy between 1990s cryptography export controls (the 'crypto wars,' e.g. U.S. munitions-list restrictions on strong encryption) and current-day export controls or governance proposals around AI model weights. Without the full text, the likely argument concerns whether restricting distribution of a a piece of information/software (encryption algorithms then, model weight files now) is technically enforceable given that both are ultimately just data that can be copied and distributed. This is relevant to practitioners tracking AI export control policy (e.g. U.S. BIS rules on frontier model weights) who want historical precedent for how similar restrictions played out for cryptographic software.

Hacker News · 142 ptsRunnable

Run Kimi K3 using 29 GB of RAM at 0.50 tok/s

Running a giant AI model on a laptop's worth of RAM — technically works, painfully slow.

Kimi K3 is a very large AI language model that normally needs a lot of expensive computer memory to run. This piece is about squeezing it down to run on just 29 GB of RAM, which is roughly what a well-specced laptop or desktop has, rather than the server-grade hardware such models usually demand. The catch is speed: it runs at about half a token (roughly half a word) per second, meaning a single sentence could take a minute or more to generate. It's a demonstration of the tradeoff between accessibility and performance — showing that huge AI models can technically run on modest hardware if you're willing to wait, which matters for anyone without access to expensive GPU clusters who still wants to experiment with cutting-edge models.

Technical view

The post demonstrates running Kimi K3, a large-scale model, within a 29 GB RAM budget — well below its typical deployment footprint — almost certainly via aggressive quantization and/or disk/SSD offloading of model weights rather than keeping everything resident in RAM or VRAM. The tradeoff is stark: throughput drops to roughly 0.50 tokens/second, illustrating the practical floor of consumer-hardware inference for frontier-scale MoE or dense models. This is useful as a proof-of-concept for practitioners exploring extreme memory-constrained local inference setups (e.g. llama.cpp-style offloading), though it's far too slow for interactive use and mainly serves as a feasibility/benchmark data point.

Hacker News · 140 ptsConceptual

Situational Awareness down 67% in July in AI stock rout

An AI-stock index nicknamed 'Situational Awareness' lost two-thirds of its value in one month.

There's a stock index or fund nicknamed 'Situational Awareness' (echoing the famous AI-forecasting essay of the same name) that tracks companies riding the AI boom. In July, amid a broader sell-off in AI-related stocks, it reportedly dropped 67%, a huge swing showing how much hype and speculation had been baked into these prices. Investors piling into 'AI plays' can see gains evaporate quickly when sentiment shifts, even though the underlying technology hasn't changed. It's a reminder that stock prices track expectations and mood, not just technical progress.

Technical view

The index/fund tracking 'situational-awareness'-themed AI equities fell 67% in July, consistent with a broader correction in richly-valued AI infrastructure and application names. Drawdowns like this typically reflect multiple-compression (falling P/E or P/S ratios) rather than a change in reported fundamentals, often amplified by leveraged or thematic ETF flows. Anyone tracking AI-stock baskets should watch for correlation breakdowns between compute/model-progress narratives and equity pricing, and for concentration risk inherent to thematic indices.

Hacker News · 139 ptsConceptual

The Maxwell Conjecture Is False (GPT 5.6 Sol)

A long-standing math conjecture named after Maxwell just got disproven, reportedly with AI's help.

Mathematicians had proposed something called the 'Maxwell Conjecture,' a claim about a particular mathematical structure that had stood unresolved. New work shows the conjecture is actually false, meaning a counterexample was found that breaks the pattern everyone assumed held. Notably, the breakthrough is credited to an AI system, hinting at AI's growing role in generating or checking mathematical proofs rather than just assisting humans. This matters because disproving a conjecture reshapes what mathematicians thought was true and often opens new research directions.

Technical view

A counterexample refuting the Maxwell Conjecture has reportedly been produced, with the discovery credited to an AI model. As with other AI-assisted disproofs, the value lies in the search process, an AI exploring or generating candidate structures far faster than manual case analysis, with a human or automated verifier then confirming the counterexample satisfies the conjecture's hypotheses while violating its conclusion. Replicating or building on this would require the precise formal statement of the conjecture and the produced counterexample for independent verification.

Hacker News · 134 ptsConceptual

Arch Linux disables AUR package adoption

Arch Linux turned off the feature letting users 'adopt' abandoned community packages.

The AUR (Arch User Repository) is a community-run library where anyone can submit build scripts for software not in Arch's official repos. When a maintainer disappears, other users could 'adopt' that orphaned package to keep it updated. Arch has now disabled this adoption feature, likely because it was being exploited: bad actors could adopt a popular abandoned package and slip in malicious code, a known supply-chain attack pattern in open package ecosystems. This is a security-hardening move to protect people who install AUR packages trusting them to be safe.

Technical view

Arch Linux has disabled the AUR's package-adoption workflow, which previously let any registered user claim orphaned packages and push new PKGBUILD updates. This closes a takeover vector where an attacker adopts a stale but popular package and injects malicious build or install scripts, analogous to typosquatting and repo-hijack attacks seen in npm/PyPI. Maintainers and downstream users should audit recently-adopted packages, verify PKGBUILD provenance, and expect a revised, likely more vetted, ownership-transfer process from the Arch team going forward.

Hacker News · 133 ptsConceptual

Danube's record low levels force shutdown of Hungary's only nuclear plant

Hungary shut its only nuclear plant because the Danube got too low and warm to cool it.

Nuclear plants need huge amounts of river water to cool their reactors, and Hungary's sole plant, on the Danube, is no exception. A severe drought has pushed the river to record-low levels and raised its temperature, leaving too little cool water to safely run the reactors at full power. As a result, operators had to shut down or throttle the plant, straining a country's electricity supply that depends heavily on this one facility. It's a vivid example of how climate-driven drought can directly threaten energy infrastructure, not just farms and rivers.

Technical view

Record-low Danube water levels have forced a reduction or shutdown at Hungary's Paks Nuclear Power Plant, which relies on river water for reactor cooling and condenser heat rejection. Low flow combined with elevated intake temperatures reduces the thermal margin needed for safe cooling, forcing plants to derate or trip units under regulatory thermal-discharge and safety limits. This highlights a growing grid-resilience concern for river-cooled thermal plants broadly: cooling-water availability is becoming a climate-exposed constraint on baseload capacity, relevant to plant siting, cooling-tower retrofits, and drought contingency planning.

Hacker News · 131 ptsBuildable

Getting 25 Gbps Thunderbolt Ethernet on My Mac Studio

A hobbyist squeezed 25-gigabit networking speeds out of a Mac Studio's Thunderbolt port.

Most home and office networks run at 1 or 10 gigabits per second, but Thunderbolt, the fast port on modern Macs, can carry data much faster than typical Ethernet cabling. This write-up describes configuring a Mac Studio to push network traffic at 25 Gbps over Thunderbolt, well beyond standard consumer gear, likely using Thunderbolt networking adapters or bridging plus careful driver and switch tuning. This matters for people moving huge files, like video editors or anyone shuttling large datasets, who want workstation-to-workstation speed without buying expensive dedicated networking hardware. It's a practical hack anyone with the same port and OS could try themselves.

Technical view

The post details achieving 25 Gbps throughput over Thunderbolt on a Mac Studio, exceeding the common 10GbE ceiling by exploiting Thunderbolt's native ~40 Gbps link (or Thunderbolt-to-QSFP/SFP28 adapters) alongside macOS's Thunderbolt networking/bridging support rather than a standard Ethernet NIC. Hitting real-world 25 Gbps typically requires the right adapter/cable choice plus MTU and jumbo-frame tuning, validated with tools like iperf3 to rule out CPU or driver bottlenecks. Anyone with equivalent Thunderbolt 4/5 hardware could replicate this for high-speed workstation interconnects, such as NAS access or ML data transfer, without a full 25GbE switch upgrade.

Hacker News · 131 ptsConceptual

The most official water costs $120k a gallon

The 'purest' water on Earth, a lab reference standard, costs about $120,000 a gallon.

Not all water is equal: for extremely sensitive scientific measurements, labs need water with virtually zero impurities, so pure that even trace contaminants would throw off results. Producing and certifying this ultra-pure 'reference' water, used to calibrate instruments and verify other labs' measurements, is incredibly labor- and process-intensive, driving its price to roughly $120,000 per gallon. It earns its 'official' status because a trusted body verifies its purity down to minuscule levels, essentially certifying it as ground truth. It's a striking example of how in science, value comes from certified precision and trust, not the substance itself.

Technical view

This describes a certified reference-grade water standard, likely a national-metrology-institute Standard Reference Material, priced around $120,000/gallon due to the cost of achieving and verifying extreme purity (contaminants controlled to parts-per-trillion) plus the certification and traceability chain required for it to serve as a calibration standard. Such materials underpin measurement traceability for trace-metal analytics, isotope-ratio analysis, and instrument calibration across analytical chemistry labs. The steep price reflects that its value comes entirely from certified purity and documented chain-of-custody, not from any inherent property of the water.

Hacker News · 120 ptsBuildable

Golang proposal: container/: generic collection types

Go proposes rebuilding its list, heap, and ring data structures with modern generics.

Programming languages need 'container' tools, ready-made structures like lists, stacks, queues, or heaps that hold collections of data. Go already has some of these in an older package, but they predate Go's newer 'generics' feature, which lets code work safely and efficiently with any data type without manual type-checking tricks. This proposal suggests rebuilding or extending Go's container package using generics, making these collection types cleaner, type-safe, and easier to use correctly. For everyday Go programmers, this means less repetitive boilerplate code and fewer bugs when working with common data structures.

Technical view

The proposal targets Go's `container/` packages (list, heap, ring), pre-generics APIs that rely on `interface{}`/`any` and runtime type assertions, and would introduce or refactor generic collection types using Go's type parameters (available since Go 1.18). This would give developers compile-time type safety and eliminate runtime casts for structures like doubly-linked lists, heaps, and rings. As with prior generics-adoption efforts (e.g., the `slices` and `maps` packages), expect a phased design-review process on the Go issue tracker before it lands in the standard library; developers can prototype equivalent generic containers today to anticipate the eventual API.

Hacker News · 115 ptsConceptual

Dubious research tied to Red Bull has shaped energy drink policy

Investigation finds industry-funded studies, not independent science, shaped energy drink safety rules.

When regulators decide how much caffeine is safe in energy drinks, they lean on scientific studies, but this investigation finds that some key research behind those rules was funded or influenced by Red Bull, the industry's biggest player. That's a conflict of interest: research paid for by a company with a stake in lenient rules may downplay risks or frame questions in ways that favor that company. The report traces how this questionable research made its way into actual safety guidelines and regulatory decisions. It matters because it shows how corporate money can quietly shape the science meant to protect consumers.

Technical view

The piece traces industry-funded, Red Bull-linked studies on caffeine safety and energy-drink consumption that were subsequently cited in regulatory risk assessments or industry safety guidance, a funding-conflict pattern familiar from tobacco, sugar, and pharma research. Likely concerns include selective outcome reporting, industry-favorable study design, and citation laundering, where sponsored papers appear in the literature as if independent. For anyone evaluating nutrition or food-safety research, the actionable takeaway is to check funding disclosures and author conflicts-of-interest before treating a cited study as independent evidence in policy debates.

Hacker News · 106 ptsConceptual

Show HN: What should the GUI for AI agents look like?

Two founders ask: what's the point-and-click interface for AI agents, not chat?

Before graphical interfaces, using a computer meant typing exact commands like "COPY FILE.TXT A:" — you had to memorize syntax and recall what was even possible. The GUI invented at Xerox PARC and popularized by the Macintosh didn't add new computer abilities, it just made existing ones visible and discoverable through icons, menus, and clicking instead of memorized text. MarbleOS's creators argue today's AI agents are stuck in that same command-line era: even though you talk to them in plain English, you still have to know what to ask for and recall the right phrasing rather than seeing your options laid out. They're building an interface meant to make an agent's capabilities visible and pokeable, the way the GUI did for files and programs, instead of depending on you remembering the right words.

Technical view

MarbleOS is a proposed GUI paradigm for AI agent interaction, drawing an explicit analogy between today's natural-language agent interfaces and pre-GUI command-line computing. The core critique: natural language removed strict syntax but preserved the underlying UX problem of recall-dependent interaction — users must know and articulate what's possible rather than discovering it through direct manipulation. The implied design direction follows the Xerox PARC/Mac/NeXTSTEP lineage — surfacing agent capabilities, state, and available actions as visible, manipulable UI elements rather than a blank prompt box. As a Show HN post this is a product pitch rather than a technical paper, so no architecture or implementation details are given here; a practitioner would need to check the actual product/demo for specifics.

Hacker News · 105 ptsRunnable

How JPEG works: Interactively explore JPEG's lossy compression methods

Poke JPEG's dials yourself and watch a photo blur, block, and shrink in real time.

JPEG is the compression format behind most photos you see online, and it works by throwing away visual information you're unlikely to notice — a trick called lossy compression. This interactive tool lets you explore, step by step, the moves JPEG makes: splitting an image into small blocks, converting colors into a format that exploits blind spots in human vision, and rounding away fine detail (quantization) to shrink the file. Instead of just reading about these steps, you drag sliders and watch each one distort or block a real image, making the abstract math of compression visible. It matters because nearly every photo on the internet passes through this exact pipeline, which is why JPEGs get blocky at low quality and why certain edits degrade them.

Technical view

This is an interactive walkthrough of the JPEG lossy compression pipeline: color-space conversion (RGB to YCbCr), chroma subsampling, 8x8 block-based discrete cosine transform (DCT), quantization against a quality-dependent table, and entropy coding. The interactivity lets users manipulate parameters like quality level and observe the resulting artifacts directly on sample images, making the frequency-domain effects of quantization (blockiness, ringing) tangible rather than theoretical. It's a solid reference for anyone implementing or debugging an image codec, tuning JPEG quality settings for a product, or building intuition for DCT-based compression before tackling video codecs that reuse the same building blocks.

Hacker News · 105 ptsConceptual

The mean means nothing: data visualization to debug a latency problem

Averaging your latency numbers can hide the exact problem you're trying to find.

When engineers debug why a system feels slow, they often look at the average (mean) response time — but this piece argues that number can be actively misleading. A single average blends the fast, ordinary requests together with rare, extremely slow outliers, so the mean can look fine even when a meaningful chunk of users are having a terrible experience. Instead, the approach is to visualize the full spread of latencies — things like histograms or percentile distributions — so you can actually see clusters, spikes, and tails in the data rather than one flattened number. This matters because real debugging requires seeing the shape of a problem, not just a summary statistic that can average away the very anomaly you're hunting for.

Technical view

The piece walks through debugging a real latency issue by moving from a single summary statistic (mean) to distributional visualizations — likely histograms or percentile plots (p50/p95/p99) — to expose multimodal or heavy-tailed latency behavior the mean obscures. The key technical point is that means are not sufficient statistics for skewed or multimodal distributions common in systems performance data, such as bimodal cache hit/miss latency or GC pauses, so aggregate dashboards built on averages can read 'green' while a real subpopulation of requests is degraded. Practitioners can apply this directly by swapping mean-based alerting and dashboards for percentile- or histogram-based views when triaging performance regressions.

Hacker News · 103 ptsConceptual

Moonshot’s Kimi uses 20k Nvidia chip cluster from Alibaba

Chinese AI lab Moonshot reportedly trains its Kimi model on 20,000 Nvidia chips rented from Alibaba.

Moonshot AI is the company behind Kimi, a large AI model competing with the likes of ChatGPT and DeepSeek out of China. Training and running big AI models requires enormous amounts of specialized computing hardware, particularly Nvidia's GPUs (graphics chips repurposed for AI math), and this report says Moonshot is using a cluster of 20,000 of them supplied by Alibaba's cloud arm rather than building its own from scratch. It matters because U.S. export restrictions have made it harder for Chinese companies to buy top-tier Nvidia chips directly, so arrangements like this — renting compute from a domestic cloud giant — are one of the key workarounds shaping how competitive Chinese AI labs stay despite the trade restrictions.

Technical view

According to the linked report, Moonshot AI's Kimi models are trained and/or served on a roughly 20,000-GPU Nvidia cluster provisioned via Alibaba Cloud rather than self-owned infrastructure. This is notable given U.S. export controls on advanced AI chips to China, which have pushed domestic labs toward cloud-rental arrangements with hyperscalers like Alibaba that have accumulated or gained access to large GPU fleets. For anyone tracking compute supply chains or competitive positioning among Chinese AI labs, this is a data point on scale and infrastructure strategy rather than a methods disclosure — the abstract gives no model architecture or training details.