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Papers: 60 new open-access papers a day, read aloud.

Each day the app picks five papers in each of 12 fields from what arXiv announced, and notes next to each one why it made the list. Tap one and the app fetches the paper from arxiv.org, turns the equations into words, and narrates it in the voice you picked. Figures open on screen while it reads.

Selected from everything arXiv announced this day, using peer review, cross-listing, licence and how well the paper reads aloud. No popularity or citation data is used — a paper posted today has none.

List for 25 September 2026 · refreshed daily in the app · Chorus Reader never stores or redistributes a paper; it links you to arXiv and fetches on your device

Artificial Intelligence

Learning systems, language models, and the theory underneath them.

Functional Architecture of European Electricity Trading Markets: Requirements for AI Supported Trading Systems under Regulatory Constraints

Walter Kurz, Wojtek Stricker

Artificial Intelligence · about 34 min · about 5,344 words · posted 2026-09-24 · CC BY 4.0 · 1 tables, 11 equations

  • Published in Swissi AI Journal, Volume 2026, Article SAIJ-cwo7xrcdsaut
  • 96% prose
  • Has a DOI
  • Filed in 5 fields
  • Openly licensed
  • 12 pages
Abstract

European electricity trading in the EU operates as a constrained multi-layer system in which legal design, exchange microstructure, and network physics are executed jointly across forward, day-ahead, intraday, and balancing horizons. This paper develops a functional architecture for AI-supported trading that is aligned with market-coupling mechanics, cross-zonal transfer constraints, and compliance obligations under REMIT, MiFID II, MiFIR, and EMIR. The contribution is a formal system specification composed of a decision-state vector, residual-exposure accounting, constrained optimization objective, executable-action permission gate, and fail-closed AI control logic with auditable records. The analysis maps major Nominated Electricity Market Operator (NEMO) venues and related exchange operators into an operational venue topology and identifies where cross-border coordination fails in practice: interface-level timing, permission heterogeneity, and balancing-layer coupling. The resulting framework proposes how AI can be deployed as a bounded decision component inside regulated market operation with explicit governance, rather than as an unconstrained prediction layer.

Learned Cross-Task Relationships in Multi-Task Models

Victor Zhang, Yiping Yuan, Florian Raudies, Bosun Adeoti, Brian Y. C. Leung, Sanjay Surendranath Girija, Naijing Zhang

Artificial Intelligence · about 39 min · about 6,029 words · posted 2026-09-23 · CC BY 4.0 · 7 figures, 2 tables, 6 equations

  • Published in ACM Conference on Recommender Systems
  • 94% prose
  • Has a DOI
  • Openly licensed
  • 10 pages
Abstract

We propose a framework that learns cross-task relationships in multi-task models by approximating the joint distribution of task labels through targeted pairwise relationships. This approach improves performance via transfer learning and enhances information extraction without the intractable complexity of modeling the full joint space. Although our framework applies to any multi-task system, we demonstrate its efficacy within YouTube's production recommendation systems. Experiments across the Notifications, Homepage, and Watch Next surfaces show improvements in both accuracy and user satisfaction metrics. Finally, we propose a workflow template to facilitate broader future implementation.

SMILESGNN: Interpretable Clinical Toxicity Prediction via SMILES-Graph Cross-Attention Fusion

Quang Minh Nguyen, Thuy Quynh Nguyen, Duc Minh Le, Ho Nhat Minh Nguyen, Thanh Long Dai Doan, Trong Nghia Nguyen

Machine Learning · about 17 min · about 2,693 words · posted 2026-09-23 · CC BY 4.0 · 5 figures, 3 tables, 1 equations

  • Published in International Conference on Multimedia Analysis and Pattern Recognition (MAPR)
  • Has a DOI
  • 96% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Drug toxicity prediction is critical for reducing late-stage attrition in drug discovery, yet remains challenging due to severe class imbalance, scaffold-based generalization, and the clinical need for interpretable predictions. Single-modality approaches-SMILES Transformers or graph neural networks capture complementary aspects of molecular structure, while sequence-only models cannot directly provide graph-attributed explanations. We present SMILESGNN, a multimodal architecture that fuses a SMILES Transformer encoder and a GATv2 graph encoder via cross-attention, and SMILESGNN-PT, a variant using a ChemBERTa-2 pretrained backbone. The design retains an explicit graph branch within the predictive pipeline, supporting GNNExplainer-based analysis of substructures associated with toxic predictions. On ClinTox, SMILESGNN achieves AUC-ROC 0.987 and F1 0.906 with only 0.4M parameters, performing competitively with a strong SMILESTransformer and a larger ChemBERTa-2/GATv2 concat-fusion baseline. On Tox21 (12 tasks), SMILESGNN-PT obtains mean AUC-ROC 0.750, comparable to ChemBERTa-2 alone and the same-backbone concat-fusion baseline. Overall, the results suggest that cross-attention is a practical fusion alternative that preserves competitive predictive performance while enabling graph-based interpretability support.

Uncovering Residential PV-EV Co-Adoption from Smart-Meter Data: Load Archetypes and Detection for Demand-Side Planning

Jack Zheng, Hao Wang

Machine Learning · about 41 min · about 6,356 words · posted 2026-09-23 · CC BY 4.0 · 1 figures, 8 tables, 3 equations

  • Published in Next Energy
  • 96% prose
  • Has a DOI
  • Openly licensed
Abstract

The increasing adoption of electric vehicles (EVs) and rooftop photovoltaic (PV) systems is reshaping residential electricity demand and creating new challenges for demand-side management (DSM), tariff design, and low-voltage network planning. Much of the existing literature examines EV charging or PV generation in isolation, leaving the behavioral dynamics of household co-adoption less understood. We develop an integrated, two-part workflow to analyze advanced metering infrastructure (AMI) data. A discovery component applies dynamic time warping (DTW) k-means with DTW barycenter averaging to cluster daily import or export profiles into interpretable behavioral archetypes, while a predictive component trains a bidirectional long short-term memory (BiLSTM) model on 21-day windows and benchmarks it against tabular baselines for PV/EV activity detection. The EV activity labels are inferred from charging-like load signatures because charger measurements are unavailable. Using half-hourly AusNet residential data from Victoria, Australia, the clustering uncovers distinct patterns across PV-only, EV-only, co-adoption, and neither cohorts; for co-adopters, a midday-centered weekday export archetype accounts for approximately 50% of days. At validation-tuned thresholds, both BiLSTM and XGBoost achieve strong discrimination. BiLSTM obtains 0.991 for the area under the receiver operating characteristic curve (AUROC), 0.906 for macro-F1, and the highest recall on the most difficult class (0.836 for EV-only recall). Tree-based baselines remain competitive. Performance remains stable across plausible labeling rules (macro-F1: 0.894--0.914) and strictly forward temporal splits (macro-F1: 0.894--0.906).

MORE-PLR: multi-output regression employed for partial label ranking

Santo M. A. R. Thies, Juan C. Alfaro, Viktor Bengs

Machine Learning · about 40 min · about 6,200 words · posted 2026-09-24 · arXiv non-exclusive licence · 5 figures, 6 tables, 26 equations

  • Published in Machine Learning
  • 91% prose
  • Has a DOI
  • Code or project page linked
Abstract

The partial label ranking problem is a supervised learning scenario that aims to fit a preference model that predicts a bucket order defined over a set of labels for a given input instance. This problem generalizes the well-known label ranking problem, which, in practice, is limited to outputting total orders of labels. Existing partial label ranking methods have primarily extended label ranking approaches to handle ties in predictions. This paper proposes using multi-output regression to address the partial label ranking problem, introducing an encoder that, during the learning phase, transforms the (possibly incomplete) rankings with ties of labels to multivariate regression targets, an underexplored perspective in both label ranking and partial label ranking. Moreover, during the inference phase, we introduce several post-hoc layers that convert the multi-output regression results into the output bucket order to effectively implement this approach. This framework provides learning strategies that are competitive with the current state-of-the-art partial label ranking methods, as demonstrated through experimental evaluations.

Language and Speech

How machines read, write, translate, and listen.

Calibration is the Bottleneck: An Action-Class Diagnostic of Multi-Turn Tool-Calling

Kangjia Zhao, Jiajun Li, Haozhan Shen, Wei Chow, Linfeng Li, Hang Song, Lingdong Kong, Chen Zhi, Tiancheng Zhao, Songhua Liu, Jianwei Yin

Computation and Language · about 42 min · about 6,570 words · posted 2026-09-01 · CC BY 4.0 · 2 figures, 17 tables, 1 equations

  • Accepted at EMNLP
  • 89% prose
  • Filed in 2 fields
  • Code or project page linked
  • Openly licensed
Abstract

Multi-turn tool calling is a core evaluation scenario for large language model (LLM) agents. On public tool-calling benchmarks, open-weight models now approach or even surpass closed-source frontier models in aggregate accuracy. However, this metric averages over many different multi-turn situations and obscures whether progress is balanced across them. We propose an action-class-oriented diagnostic framework that decomposes multi-turn failures into two orthogonal modes: action-class miscalibration and action-execution failure. The framework operates over a four-class action space (TOOL_CALL/ASK/REFUSE/CONFIRM) and introduces a self-revealing upper bound Acc <= GAR (Gold Action Recall); the two modes show up as bound violation (Acc > GAR, exposing state-grader masking of miscalibration) and large bound slack (GAR >> Acc, localizing execution failure within TOOL_CALL). We validate it on a panel of tool-calling models across multiple multi-turn benchmarks. Across our panel, the diagnostic reveals action-class miscalibration as a substantial failure mode the state grader cannot see. This gap inflates standing for heavily tool-trained families, which our diagnostic separates from families with context-appropriate action choice. Calibration is reshapable through context-only perturbations, but the reshape is heterogeneous: a single perturbation moves accuracy in opposite directions across families (up to +11.5 vs -21.0 pp on the same scenario), and its effect further depends on the perturbation mechanism. We argue that multi-turn tool-calling evaluations should supplement aggregate accuracy with action-class diagnostics that expose what the model actually does in each scenario.

Temporal Taxation Compounds Under Post-Training Compression of Whisper Models

Srishti Ginjala, Eric Fosler-Lussier, Christopher W. Myers, Srinivasan Parthasarathy

Computation and Language · about 44 min · about 6,806 words · posted 2026-09-23 · CC BY 4.0 · 5 figures, 4 tables, 1 equations

  • Accepted at EMNLP
  • 95% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Automatic speech recognition models are audited for demographic fairness at full precision, yet the models that ship to production have been quantized, pruned, and distilled. We ask whether post-training weight compression, which alters model weights rather than the audio signal or its feature representation, redistributes error burden across demographic groups. Across the Whisper family on Fair-Speech, Common Voice 25, and AfriSpeech-200, 50% Wanda pruning of Whisper-large-v3 sharply widens the Black/AA-vs-Asian temporal-taxation differential on Fair-Speech: the absolute word-error-rate gap between the worst- and best-served groups more than doubles; at an assumed cost of five seconds of correction effort per transcription error this is a rise from 30 to 64 seconds of correction time per minute of speech. This +111% relative increase is invariant to the assumed per-error cost, survives an audio-quality control, and is only partly mitigated by beam-search decoding, which still leaves an +86% increase. At edge model size, INT4 HQQ quantization compounds catastrophic transcript loops on West African accents by factors of five to seven. Distillation, by contrast, narrows demographic gaps in 21 of 27 evaluated settings (teacher-student pair, precision, and dataset), with the exceptions concentrated on a single model pair. We cast the temporal-taxation construct of Choi and Choi (2025) as a quantitative metric, and show that single-snapshot fairness audits on full-precision models do not capture the deployment-time burden that compression places on already-marginalized speakers.

From Policy Documents to Structured Survey Responses: Evaluating Large Language Models for Policy Monitoring

Carolyn Cole, Matthias Deschryvere, Toqeer Ehsan, Arash Hajikhani

Computation and Language · about 46 min · about 7,187 words · posted 2026-09-24 · CC BY 4.0 · 4 figures, 8 tables

  • Accepted for publication
  • 100% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
Abstract

Science, technology, and innovation policies are crucial for competitiveness, yet their diversity and scale make them difficult to map and monitor consistently. Existing approaches rely heavily on manual survey efforts, which are costly and challenging to scale across countries. Large language models (LLMs) enable new possibilities for extracting and structuring information from long and unstructured policy documents. This paper presents an application of LLMs as "AI respondents" for generating structured survey responses from policy texts. We develop a data extraction pipeline based on long-context in-context learning to map information from public web sources into predefined survey categories, including policy instruments, target groups, and thematic areas. The pipeline integrates a validation step using a secondary LLM to assess relevance and evidence, alongside comparisons with human-provided responses. Using a multi-country dataset, we evaluate the alignment between LLM-generated and human-generated outputs through overlap measures and cross-validation. Results show that LLMs achieve high agreement for structured indicators (84-95%), while differences remain in free-text fields, where models tend to provide more detailed procedural descriptions. These findings highlight the potential of hybrid human-AI workflows for policy monitoring, improving both efficiency and scalability while maintaining the need for human validation and contextual interpretation.

Cultural Divergence Preservation: Diagnosing Flattening and Caricature in LLM-Simulated Survey Populations

Yeeun Chae, Yewon Choi, Seunghyun Lee, IL Im

Computation and Language · about 29 min · about 4,518 words · posted 2026-09-24 · CC BY 4.0 · 2 figures, 11 tables, 3 equations

  • Accepted at EMNLP
  • 97% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Large language models (LLMs) are increasingly used as synthetic survey respondents to estimate population response distributions. In cross-cultural survey simulation, evaluations should assess not only distributional fidelity within countries but also whether differences across countries are preserved. However, existing distance-based metrics such as Jensen--Shannon divergence (JSD) do not directly capture such cross-country differences. To address this limitation, we introduce Cultural Divergence Preservation (CDP), a reference-light diagnostic based on a one-time human calibration. CDP identifies reduced cross-country divergence as cultural flattening and increased divergence as cultural caricature. To evaluate CDP, we conduct experiments across four LLM backbones, three persona-based prompting methods, and two survey domains, the World Values Survey (WVS) and the Big Five Personality Test. The results reveal a systematic discrepancy between conventional fidelity metrics and CDP. Controlled experiments show that CDP changes monotonically as cross-country divergence is attenuated or amplified, while the corresponding changes in JSD remain relatively small. In our audit of real LLM generations, DeepPersona-Inspired prompting is frequently favored by conventional fidelity metrics but exhibits the strongest flattening in every model--domain block. CDP thus complements fidelity metrics by directly quantifying the attenuation or amplification of cross-country divergence.

Does a model's stated reason for rejecting a candidate do any work?

Archit Rastogi

Computation and Language · about 43 min · about 6,639 words · posted 2026-09-24 · CC BY 4.0 · 2 figures, 4 tables

  • Accepted for publication
  • 94% prose
  • Filed in 3 fields
  • Code or project page linked
  • Openly licensed
Abstract

Asked to choose between candidates and explain the choice, a language model often rejects a rival by naming a fact its profile lacks: no director, no date of death. That sentence is a claim about the text in front of the model, and it can be tested without any judge. We insert a real corpus sentence stating the named fact into the rival's profile and ask again under greedy decoding. Two controls separate content from placement: a length-matched irrelevant sentence at the same profile, and the same two sentences at a third option the model never mentioned. In the largest of three runs, six open models on 2WikiMultihopQA, supplying the named fact at the profile the model named moves its choice more than the irrelevant control does, odds ratio 3.57 [1.54, 8.26], Holm p=0.0210, and this survives dropping any single model. The contrast the design was built to detect, the same fact at the option nobody named, does not clear correction, Holm p=0.2428. The strongest result in the family carries no content claim at all: the identical irrelevant sentence moves the choice more at the named rival than at the third option, Holm p=0.0008. Repair and control also differ in co-candidate mentions, relation template and fluency; post-hoc matching on the first two preserves the content effects' direction, matching fluency weakens one, so the content contrasts bound an effect rather than establish one. A forced single-token probability read disagrees in direction with the free-text choice on that same contrast, and three candidate explanations for the disagreement find no support. Every measurement is a string rule, so each was validated against the records it reads; validation caught eight defects. The largest, a choice-parsing rule that returned the option a model had just rejected in 17.1% of adjudicable responses, would have reported six surviving contrasts instead of four.

Vision and Graphics

Seeing, rendering, and reconstructing the visual world.

Small yet Assistive: Spatially-Aware Post-Training for Low Vision

Rishabh Choudhary, Shreyansh Raj, Umesh Goyal, Shubh Kashyap, Shrestha Kumar, Sushovan Jena, Komal Kumar, Hisham Cholakkal, Aditya Nigam

Computer Vision · about 36 min · about 5,541 words · posted 2026-09-23 · arXiv non-exclusive licence · 5 figures, 14 tables, 3 equations

  • Accepted at EMNLP
  • 98% prose
  • Filed in 2 fields
  • 14 pages
Abstract

An estimated 1 billion people worldwide live with vision impairment, yet current vision-language models (VLMs) produce descriptions too vague for safe navigation by blind and low-vision (BLV) users. Large VLMs can generate high-quality audio-description-compliant narrations but cannot run on mobile devices; small VLMs offer competitive latency but lack spatial detail, directional cues, and hazard awareness for navigational assistance. We present Smol-VL-BLV, a compact VLM for blind and low-vision users that closes this gap using a 500M decoder transformer model and two post-training mechanisms: (1) teacher-student distillation and (2) Group Relative Policy Optimization (GRPO) with a composite BLV reward targeting directional language, metric distances, and hazard detection. Because multi-stage post-training can induce catastrophic forgetting, we add a lightweight finetuning stage after the last stage GRPO finetuning to recover general descriptive quality while preserving BLV-specific spatial grounding. Our best model substantially outperforms the baseline across various benchmarks, including tasks: VQA, BLV captioning, OCR, and latency. Compared with the baseline for relative improvement, it improves the Spatial score gain of 19.3%, and the Social score gain of 14.8%. It also increases OCR-Bench by 101.5%, and raises TextVQA accuracy by 44.2%. These results show that BLV-focused post-training improves both accessibility-specific spatial grounding and general visual-text reasoning. Deployed on a mid-range Android smartphone via Mixed-Precision Quantization, the model remains approx. 450 MB and runs entirely on-device, offline and without network dependency, generating descriptions with latency dependent on host hardware capabilities. Our model, dataset, and code is publicly released at https://smol-vl-blv.github.io/Smol-VL-BLV-website/

Beneath the Scores: Rethinking Hallucination Evaluation for Video Understanding Models

Shuzhi Gong, Fengze Sun, Yuansan Liu

Computer Vision · about 60 min · about 9,373 words · posted 2026-09-24 · CC BY 4.0 · 6 figures, 15 tables

  • Accepted at NeurIPS
  • 99% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Video understanding is increasingly performed by multi-stage LLM agents that separate temporal grounding, visual observation, and reasoning. Yet these stages are typically evaluated on different benchmarks and distributions, making it difficult to determine where hallucinations originate. We first organize existing benchmarks around these stages and show that their scores provide inconsistent diagnostic signals: stronger stage-level performance does not reliably imply lower downstream hallucination, and even benchmarks targeting the same capability can disagree. We therefore introduce a causal stage-intervention protocol that overwrites individual stages while holding the downstream task fixed. Across 60,008 runs on three video-agent architectures, we find that grounding is the dominant source of downstream error, with roughly four times the causal impact of corrupting visual observations. Successful grounding depends primarily on locating the correct region rather than precise temporal overlap, explaining why standard mIoU metrics poorly predict downstream reliability. We further find that incorrect evidence is substantially more harmful than missing evidence. Finally, auditing existing benchmarks against these interventions reveals that their scores do not reliably predict causal cascade sensitivity and can fail under distribution shift. These results motivate intervention-based, stage-aware evaluation for trustworthy video agents.

Mind the Gap: Mesh-Guided Repair of Broken Vessels

Gniewosz Drwiega, Wojciech Szymanski, Marek Wodzinski

Computer Vision · about 26 min · about 4,105 words · posted 2026-09-24 · CC BY 4.0 · 5 figures, 3 tables

  • Accepted at MICCAI
  • 98% prose
  • Openly licensed
  • 17 pages
Abstract

Vessel segmentation is commonly optimized as voxel-wise classification, but small local errors can strongly disrupt vascular connectivity while having little effect on overlap scores. This is particularly problematic for downstream analyses that rely on centerlines, branches, connected components, or graph structure. We propose a mesh-guided post-processing framework for repairing broken vessel segmentations produced by nnU-Net. For each predicted binary mask, a deformable template mesh is fitted to the mask surface in physical space and used as a case-specific geometric scaffold. The fitted mesh is not voxelized as the final segmentation; instead, it guides conservative reconnection of disconnected components by proposing or validating thin bridge candidates under foreground-growth constraints. We evaluated this approach in three vascular anatomies using AortaSeg24 and SEGA for the aorta, TopCoW for the Circle of Willis, and PARSE for the pulmonary arteries. Performance is measured using Dice, connected-component Dice (ccDice), and the Betti-0 number. Across these datasets, repair substantially improved connectivity while preserving overlap: Dice remained nearly unchanged, whereas ccDice increased from 0.596 to 0.992 for aorta, from 0.722 to 0.835 for TopCoW, and from 0.028 to 0.862 for PARSE. The FOMAML meta-initialization further accelerated the fitting per-case, supporting practical mesh-based repair of the vascular topology. These results suggest that explicit mesh representations can provide a useful geometric prior for correcting topological failures in otherwise accurate voxel segmentations.

OREO: Fidelity Alignment in 3D Generation via On-the-fly Rendering-Editing Optimization

Zhiyuan Ma, Wenbo Hu, Wang Zhao, Pengfei Wang, Ying Shan, Lei Zhang

Computer Vision · about 35 min · about 5,463 words · posted 2026-09-24 · arXiv non-exclusive licence · 12 figures, 4 tables, 12 equations

  • Accepted at ECCV
  • 92% prose
  • Filed in 2 fields
  • Code or project page linked
Abstract

Despite recent advancements in 3D generation, models often struggle to produce assets with high visual fidelity. To bridge this gap, we propose OREO, an alignment framework that enhances the realism of 3D generators by leveraging rich 2D diffusion priors. Instead of relying on static datasets, OREO establishes a dynamic optimization loop that produces on-the-fly edited renderings as 2D pseudo-targets. At its core, we introduce Reinforced Editing, which utilizes a 2D model to refine rendered views of the 3D output, enhancing their overall visual fidelity while preserving the underlying geometry, viewpoint, and content. These refined views serve as high-quality supervision targets, enabling the 3D generator to learn from its own generated samples and progressively improve its visual quality. Experiments demonstrate that OREO effectively improves upon pre-trained baselines, producing 3D assets with enhanced visual realism.

OmniFabric: Coherent UV Space Texture Synthesis for 3D Garment Reconstruction

Ding-Jiun Huang, Yuanhao Wang, Cheng Zhang, Hugo Bertiche, Alexandru-Eugen Ichim, Thabo Beeler, Fernando De la Torre

Computer Vision · about 44 min · about 6,772 words · posted 2026-09-24 · CC BY 4.0 · 12 figures, 5 tables, 3 equations

  • Accepted at SIGGRAPH
  • 97% prose
  • Code or project page linked
  • Openly licensed
Abstract

Automated generation of production-ready 3D garment assets from a single image is a central challenge in digital content creation. While recent generative models have significantly advanced 3D geometry reconstruction, synthesizing high-quality textures remains a bottleneck. Existing methods often bake environmental illumination and shadows directly into the texture map, or they fail to maintain global structural coherence, making the resulting assets unusable for physical simulation and relighting. In this work, we introduce OmniFabric, a novel approach that synthesizes globally coherent texture maps directly within the 2D sewing pattern space. Given a single reference image, our pipeline utilizes an estimated 3D mesh and generative priors of powerful Vision-Language Models (VLM) to establish a complete but coarse texture initialization across the unwrapped sewing patterns. We then leverage a specialized diffusion transformer, trained via an automated synthetic data engine and conditioned on 3D positional features, to refine this initialization directly in the canonical UV domain. This effectively removes distortion and baked-in artifacts to extract a clean and normalized texture map that preserves the original garment design. Extensive experiments demonstrate that OmniFabric significantly outperforms state-of-the-art baselines, yielding photorealistic 3D garments with high-quality textures.

Robotics and Control

Machines that move through the world and decide how.

System Identification of an Octocopter in Hover using Full-Harmonic Orthogonal Multisine Inputs

Justin J. Matt, George V. Altamirano

eess.SY · about 70 min · about 10,918 words · posted 2026-09-24 · CC0 · 12 figures, 3 tables, 61 equations

  • Published in AIAA Journal of Aircraft, Article in Advance
  • 95% prose
  • Has a DOI
  • Filed in 3 fields
  • Openly licensed
  • 31 pages
Abstract

A new method for multi-input flight maneuver design for system identification is presented. The method consists of injecting "full-harmonic" orthogonal multisine signals into the flight control system. Orthogonality is achieved by repeating maneuvers with changing multisine polarities. The multisines can contain the same frequency content, which can simplify frequency response estimation and allow for long flight maneuvers to be split into several shorter maneuvers while maintaining the same frequency resolution and minimum frequency. An input allocation scheme is presented that augments the multisines to size the vehicle response amplitude about a specific degree of freedom. The developed approach was demonstrated through flight testing of a small octocopter in near-hover conditions. The input allocation scheme was utilized successfully to increase excitation about the yaw axis. Electrical power, motor speed, and rigid-body dynamic models were identified and are shown to predict the vehicle and motor responses accurately. The models are parameterized primarily by rotor thrust and torque coefficients, making them suitable for analysis of aircraft flight dynamics and individual rotor aerodynamics. The results demonstrate that the near-hover flight dynamics can be modeled accurately by neglecting rotor hub moments, variations in rotor coefficients, gyroscopic moments in roll and pitch, and aerodynamic interaction effects.

Iterative Learning Control of the Cooling Rate in a Dual-Laser Powder Bed Fusion Process

Lauren Bogo, Adam Clare, Dominic Liao-McPherson

eess.SY · about 25 min · about 3,934 words · posted 2026-09-23 · CC BY 4.0 · 9 figures, 2 tables, 13 equations

  • Published in IEEE Conference on Control Technology and Applications (CCTA), Vancouver, BC,…
  • 92% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
Abstract

The thermal history of the melt pool in laser powder bed fusion (LPBF) additive manufacturing processes governs the solidification microstructure and the mechanical properties of the resulting 3D-printed parts. Dual-laser systems offer additional degrees of freedom to control the cooling profile by reheating material behind the melt pool, but calibrating process parameters is challenging due to the complex physics of the process. We present an optimization-based iterative learning controller that determines optimal power, velocity, and offset settings by judiciously combining simulations and experiments: the model supplies search directions while feedback obtained from experiments on the real plant corrects for parameter errors, enabling convergence despite model inaccuracies. The approach is validated in simulation using a high-fidelity thermal model as a plant surrogate, with deliberate mismatches in absorption coefficient, latent heat treatment, and powder-bed effective conductivity between plant and model. Results show that the controller drives the plant cost down by over an order of magnitude and reaches a tight band of low-cost solutions across seeds, while model-only feedforward optimization stalls at a substantially higher plant cost despite appearing to converge on the surrogate.

Fast Frame Rate Estimation in Electromagnetic Side-Channel Attacks on Public Systems

Alyson Isaluski, Leonardo Teodoro, Kleber V. Cardoso, Antonio Oliveira-Jr, Saulo Queiroz

Signal Processing · about 12 min · about 1,935 words · posted 2026-09-24 · CC BY 4.0 · 1 figures, 8 equations

  • Published in extended Proceedings of the XXVI Brazilian Symposium on Cibersecurity (SBSEG)
  • Has a DOI
  • Filed in 3 fields
  • 91% prose
  • Openly licensed
Abstract

Frame refresh rate estimation is a fundamental step in identifying compromising harmonic frequencies in electromagnetic side-channel attacks. Methods based on discrete linear autocorrelation (DLA) are robust across different scenarios and require a computational complexity of $O(N\log N)$ for a signal containing $N$ samples. This work proposes reducing this complexity to $O(N)$ by exploiting prior knowledge of the target system's display resolution, as is available for certain models of the Brazilian electronic voting machine. Experiments using software-defined radios show that the proposed method preserves the accuracy of the conventional approach in the evaluated scenarios.

Modeling Load-, Velocity-, and Temperature-Dependent Transmission Errors of Cycloidal Drives for Industrial Robots Using Fourier Series

Christian J. E. Bauer, Valentin Kamm, Marcel Dzubba, Lukas Steinle, Armin Lechler, Alexander Verl

Robotics · about 27 min · about 4,123 words · posted 2026-09-24 · arXiv non-exclusive licence · 7 figures, 1 tables, 13 equations

  • Published in IEEE International Conference on Industrial Technology (ICIT). Wuhan, China:…
  • 91% prose
  • Has a DOI
  • Filed in 4 fields
Abstract

Industrial robots are rarely used for machining tasks due to their limited path accuracy. This accuracy is mainly limited by inaccuracies in the drive trains. Compliance and transmission errors occur in the joint gearboxes. While transmission errors have been extensively studied for strain wave gears, there is little research on these errors in cycloidal drives. This gearbox type is commonly used in industrial robots for medium to heavy payloads. It is proposed to model the mainly periodic transmission errors using a Fourier series where amplitude and phase are defined as a polynomial function of the main influence factors load-torque, velocity, and temperature. Measurements of the transmission errors were conducted using an experimental setup representing a single robot joint. In the evaluation of the measurement data, harmonic frequencies were related to mechanical properties of the cycloidal drive. These frequencies were used to identify the parameters of the polynomial Fourier series model. Compared to validation measurements, the derived model shows an average root mean square error of 0.026 mrad. It is proposed to use the output of the resulting model in a feedforward control approach to compensate the transmission errors and to increase the path accuracy of industrial robots.

FMCW-LIO: A Doppler LiDAR-Inertial Odometry

Mingle Zhao, Jiahao Wang, Tianxiao Gao, Chengzhong Xu, Hui Kong

Robotics · about 38 min · about 5,942 words · posted 2026-09-24 · arXiv non-exclusive licence · 9 figures, 3 tables, 28 equations

  • Published in IEEE Robotics and Automation Letters
  • 91% prose
  • Has a DOI
  • Filed in 4 fields
Abstract

Conventional LiDAR-inertial odometry (LIO) or simultaneous localization and mapping (SLAM) methods heavily rely on geometric features of environments, as LiDARs primarily provide range measurements instead of motion measurements. From now on, however, the situation changes thanks to the novel Frequency Modulated Continuous Wave (FMCW) Doppler LiDARs. FMCW Doppler LiDARs not only offer the point range with high resolution but also capture the instant point Doppler velocity through the Doppler effect. In the letter, we propose FMCW-LIO, a novel and robust LIO, leveraging intrinsic Doppler measurements from FMCW Doppler LiDARs. To correctly exploit Doppler velocities, a motion compensation method is designed, and a Doppler-aided observation model is applied for on-manifold state estimation. Then, dynamic points can be effectively removed by the Doppler criteria, deriving more consistent geometric observations. FMCW-LIO eventually achieves accurate state estimation and static mapping, even in structure-degenerated environments. Extensive experiments in diverse scenes are performed and FMCW-LIO outperforms other algorithms on both accuracy and robustness.

Computing Systems

Architecture, networks, databases, and making software fast.

An Empirical Analysis of Cross-OS Portability Issues in Python Projects

Denini Silva, MohamadAli Farahat, Marcelo d'Amorim

Software Engineering · about 52 min · about 8,121 words · posted 2026-09-22 · CC BY 4.0 · 2 figures, 10 tables

  • Published in MSR 2026: Proceedings of the 23rd International Conference on Mining Software…
  • 99% prose
  • Has a DOI
  • Openly licensed
Abstract

While Python is designed as a cross-platform language, real-world applications encounter portability failures when deployed across different operating systems. We present the first large-scale empirical study of cross-OS portability issues in Python, analyzing 2,042 open-source repositories using two complementary approaches: systematic cross-OS test reexecution and manual analysis of GitHub issues. Our cross-platform testing of 500 projects reveals that 11.2% exhibit OS-dependent test failures. Through systematic analysis of 240 GitHub issues, we confirm 102 genuine portability problems spanning 95 additional projects. We develop a comprehensive taxonomy identifying 7 primary failure categories - with file/directory operations, process management, and library dependencies being most prevalent - along with 24 distinct sub-categories, 15 diagnostic signatures, and 4 systematic repair patterns. Our evaluation reveals that existing static analysis tools provide minimal support for portability detection, while large language models achieve 40-79% accuracy in identifying issues and 50-77% success in generating fixes when provided with structured guidance. Through 33 contributed pull requests, we demonstrate practical applicability and developer acceptance (17 merged, zero rejected) of our findings. This work establishes the first comprehensive baseline for understanding and addressing cross-OS portability issues in Python, providing actionable insights for developers, tool designers, and the broader research community.

Virtual Backhaul Connectivity for Enhanced Coverage in Fiber-Less Areas

Hao Lin, Mustafa A. Kishk, Mohamed-Slim Alouini

cs.NI · about 31 min · about 4,764 words · posted 2026-09-22 · CC BY 4.0 · 5 figures, 1 tables

  • Published in H. Lin, M. A. Kishk and M. -S. Alouini, IEEE Wireless Communications
  • 99% prose
  • Has a DOI
  • Openly licensed
Abstract

This article provides an overview of potential alternatives for providing wireless backhaul in regions that suffer from the lack of fiber optic-connectivity to the core network. These regions can be rural and remote locations, low-income neighborhoods in urban and suburban regions, and post-disaster locations suffering from the destruction of cellular infrastructure. For these scenarios, extending fiber optic cables to such locations might be extremely expensive, impractical, or simply not feasible. Hence, in order to enhance the backhaul connectivity in these scenarios, we study the potential and applicability of the integrated access and backhaul (IAB) technique, and a hybrid combination of IAB and non-terrestrial networks (NTN) that includes high/low altitude platforms (HAPs/LAPs) and low earth orbit (LEO) satellites. We conclude this article by discussing the design considerations and potential research problems that would enable efficient deployment of such solutions.

Where Does Streaming State Cost Go? A Reproducible Comparison of Flink and Kafka Streams on Kafka

Kiran N Kumar, Santhosh Kumar Saminathan

cs.DC · about 31 min · about 4,750 words · posted 2026-09-23 · CC BY 4.0 · 2 figures, 3 tables

  • Published in Kiran N Kumar, Santhosh Kumar Saminathan, "Where Does Streaming State Cost Go…
  • 100% prose
  • Has a DOI
  • Openly licensed
Abstract

This paper presents a controlled comparison of exactly-once Kafka pipelines implemented with Apache Flink and Kafka Streams, two engines with different state-management architectures. The state management in Flink occurs through checkpoints in external storage, whereas Kafka Streams restores local state by replaying broker changelogs. The experiments evaluate the effects of the two designs on latency, resource consumption, configuration sensitivity, and recover from injected failures. The engines produced expected outputs across 50 correctness trials, five for each engine-workload combination (exact 95% CI 0.929-1.000). The latencies, however, showed differences when tested in 30 minute trials at a fixed rate of 100 events/sec. The measured ingestion to output interval was 4-6 ms for stateless workloads and 4.3-6.2 s for windowed workloads. The median p99 was 1.97-1.97s for stateless workloads and 5.68-9.92s for windowed respectively. Further, a sensitivity study showed that increasing the durability interval from 1,000 to 10,000 ms shifted the latency distributions in Kafka Streams and Flink between stages. Kafka Streams' W3 median p99 T2-T1 increased from 6,085 to 23,155 ms; Flink's T3-T2 increased from 732 to 8,702 ms. Failure injection experiments demonstrate that latency can interfere with incomplete processing behavior. The results show that exactly-once correctness is a necessary but insufficient measure of stream processing performance. Kafka Streams completed 0/5 stateful JVM-kill and 1/5 in each stateful local-volume-loss trials, while corresponding Flink cells completed 5/5. The cost, placement and magnitude depend on state management, architecture, configuration, and measurement location. Accordingly, evaluations of fault-tolerant streaming systems should holistically measure latency, completion, recovery behavior, and correctness.

Model-Based Retargeting to Many-Core CPS: Simulink-to-OpenCL Workflow

Ryuga Chiba, Hiroshi Fujimoto, Takuya Azumi

Software Engineering · about 29 min · about 4,433 words · posted 2026-09-24 · arXiv non-exclusive licence · 6 figures, 3 tables

  • Published in Software Engineering and Advanced Applications
  • 100% prose
  • Has a DOI
  • 16 pages
Abstract

This paper addresses the software portability gap between Model-Based Development (MBD) and advanced many-core execution for Cyber-Physical Systems (CPS). We present a workflow-preserving retargeting approach for Simulink-based CPS applications with candidate-wise data parallelism to OpenCL-based many-core processors. Rather than manually rewriting models for new platforms, our toolchain uses MathWorks GPU Coder to extract data-parallel CUDA code, which is then translated into OpenCL host and device code via a custom framework. The conversion handles syntax rewriting, API emulation, and platform-specific argument packing. We deployed this workflow for a computationally intensive Frenet-frame trajectory planner on the Kalray MPPA Coolidge2. The results demonstrate the feasibility of a workflow-preserving retargeting pipeline for the evaluated CPS workload and platform.

CodeGraph: Open-Taxonomy Knowledge Graph for Source Code with Wikidata Grounding

Federico Pennino, Andrea Gurioli, Stefano Zacchiroli, Maurizio Gabbrielli, Paolo Ferragina

Software Engineering · about 44 min · about 6,879 words · posted 2026-09-24 · CC BY 4.0 · 12 figures, 2 tables

  • Accepted for publication
  • 97% prose
  • Has a DOI
  • Filed in 3 fields
  • Openly licensed
Abstract

Public software repositories, like GitHub and Software Heritage Archive, store billions of files, yet extracting their implicit engineering knowledge ---i.e., the algorithms they implement, the paradigms they follow, the patterns they instantiate, and the application domains they serve--- remains challenging, as current tools are constrained to syntactic and token-level analysis. We present a pipeline for building an open-taxonomy semantic annotation of source code using a code-specialised Large Language Model. The extracted entities are grounded in Wikidata through a three-stage linking procedure: a deterministic SPARQL stage handles unambiguous entities, a Deep Research Agent resolves the residual long tail, and a hierarchy-rollup stage imports the parent-of closure of each resolved Wikidata identifier. The resulting annotations are materialised as a source-code-specific open-taxonomy knowledge graph. We further introduce a calibrated quality-assurance protocol that quantifies annotation precision by combining a small human gold set with an LLM-as-a-judge filter. We applied our pipeline to the 167 million files of the Stack-Edu corpus, creating the first known large-scale open-taxonomy knowledge graph for source code. Our graph, named CodeGraph, contains approximately 158 million nodes, which include around 145 million files, about 63,000 extracted concept entities (such as algorithms, paradigms, design patterns, and application domains), and roughly 19,800 grounded Wikidata entities. Furthermore, CodeGraph features approximately 1 billion typed edges that connect files to their respective concepts, link these concepts to their grounded Wikidata identifiers, and relate them to their parent categories, covering 14 programming languages.

Security and Privacy

Attacks, defences, cryptography, and what they cost.

Automated Abstraction Refinement for Information Flow Security in Embedded Systems

Jonas Becker-Kupczok, Lukas Ernst, Paula Herber

Cryptography and Security · about 44 min · about 6,769 words · posted 2026-09-24 · CC BY 4.0 · 3 figures, 1 tables, 1 equations

  • Accepted for publication
  • 98% prose
  • Filed in 3 fields
  • Openly licensed
  • 18 pages
Abstract

Information flow analysis (IFA) is a powerful technique for verifying confidentiality and integrity and is therefore highly desirable for security-sensitive embedded systems. However, as these systems are inherently concurrent and time-dependent, existing IFA for embedded systems tend to be either imprecise or expensive. In this paper, we propose an approach to tackle this problem using automatic abstraction refinement. The key idea is to heuristically choose abstraction levels based on information about dependencies between states and detected potential information leakage. Our approach builds on previous work, where we leverage symbolic execution to precisely capture data, control, timing, and event dependencies between processes within an IFA. To capture values symbolically, this analysis uses abstract interpretation. While the existing approach requires manual definition of abstraction levels, our novel contribution in this paper is using carefully designed heuristics to select these levels automatically. The aim is to keep analysis times acceptable while also retaining enough information to decide whether or not illegal information flow is possible. We have implemented our approach for the system design language SystemC and demonstrate its feasibility with experimental results on several shared bus architectures.

A Bulletproof Business? Towards Detecting Infrastructure-as-a-Service Offerings on Telegram

Roy Ricaldi, Kristiyan Kyurkchiev, Irdin Pekaric

Cryptography and Security · about 42 min · about 6,511 words · posted 2026-09-24 · CC BY 4.0 · 3 figures, 13 tables

  • Accepted at CCS
  • 99% prose
  • Openly licensed
Abstract

Cybercriminal operations increasingly depend on reusable digital infrastructure---including hosting, proxies, and virtual private networks (VPNs)---rented through Cybercrime-as-a-Service markets and advertised on platforms such as Telegram. We present a taxonomy for identifying Telegram messages advertising cybercriminal Infrastructure-as-a-Service (IaaS). The taxonomy comprises six service categories across compute, network, and communication infrastructure, together with three trust attributes: Bulletproof, Payment Security, and Transparency. Using 261 human-annotated messages, we evaluate keyword-based and TF--IDF classifiers and examine prompt-based large language models as exploratory baselines. We select a TF--IDF pipeline and apply it to 1,116,071 messages from 167 cybercrime-related Telegram communities. The pipeline assigns at least one infrastructure category to 207,244 messages (18.57%) spanning 113 communities. Classified advertising is highly concentrated: a single community accounts for 50.3% of infrastructure-positive messages, while the trust-attribute classifiers identify Bulletproof claims in 37.66% of those messages. These findings characterize the scale, composition, and concentration of infrastructure advertising on Telegram and can inform the prioritization of communities and actors for monitoring and investigation.

zkSAS: Practical Zero-Knowledge Proofs for Verifiable Spectrum Access Management

Nishat F. Purbasha, Ifteher Alom, Eric W. Burger, Y. Thomas Hou, Wenjing Lou, Yang Xiao

Cryptography and Security · about 44 min · about 6,799 words · posted 2026-09-23 · CC BY 4.0 · 5 figures, 1 tables, 18 equations

  • Accepted for publication
  • 93% prose
  • Has a DOI
  • Openly licensed
Abstract

Dynamic Spectrum Access (DSA) through the Spectrum Access Systems (SAS) elevates spectral efficiency, yet existing centralized models face allocation logic opaqueness and a lack of independent verifiability. While blockchain-based SAS architectures offer transparency and verifiability by default, they introduce critical privacy risks and prohibitive on-chain computational overhead. We introduce zkSAS, a practical zero-knowledge proof (ZKP) system designed to address the verifiability and privacy gaps in SAS deployments, with direct applicability to both the existing CBRS SAS model and blockchain-based SAS models. The system features a suite of ZKP circuits, encompassing proofs of allocation constraint validity and proofs of move list validity to verify that channel assignments and move list-based incumbent protection measures, respectively, adhere to regulatory constraints without exposing sensitive user data. Comprehensive evaluation of our prototype in both centralized and blockchain-based settings indicates that while proof generation scales with spectrum user population, verification remains lightweight and constant-time. We envision that zkSAS offers a scalable and practical path to secure, verifiable dynamic spectrum sharing.

Blockchain-Enabled Artificial Intelligence and AI Agents for Secure Data Sharing and Cybersecurity Applications

Harsh Verma

Cryptography and Security · posted 2026-09-23 · CC BY 4.0

  • Published in International Journal of Scientific Research and Management
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
Abstract

Blockchain and artificial intelligence (AI) are converging into a single infrastructural layer for securing data sharing, model integrity, and autonomous decision-making across distributed systems. This paper presents a meta-synthesis that draws together four constituent studies covering adversarial machine learning, AI-powered anomaly detection in cloud environments, automated vulnerability patching by multi-agent large language model (LLM) pipelines, and the broader landscape of securing AI systems across their lifecycle and situates their findings within the emerging literature on blockchain-enabled AI and autonomous AI agents. Each constituent study addresses a distinct point of failure in modern AI-driven security operations: the integrity of training data and model behavior, the reliability of real-time monitoring, and the trustworthiness of automated code remediation. We argue that blockchain's properties of immutability, decentralized consensus, and verifiable provenance directly address a gap common to all three: the difficulty of establishing trust in data, models, and autonomous agents that operate without a central authority. Building on real-world research on blockchain-secured data sharing, federated learning, and multi-agent coordination, we propose a layered reference architecture that couples adversarially hardened models, blockchain-anchored data provenance, AI-driven anomaly detection, and smart-contract-governed multi-agent remediation. We conclude by identifying open problems in scalability, privacy-transparency trade-offs, and the governance of autonomous agents that must be resolved before such integrated systems can be trusted in production-critical environments.

"What I See is What I Hear": Deepfake Detection Across Diverse Hearing Abilities

Magdalena Pasternak, Malvika Jadhav, Palavi V. Bhole, Aviva Smith, Elaina Trapatsos, Vincent Bindschaedler, Roshan Peiris, Ersin Uzun, Patrick Traynor, Matthew Wright, Kevin R. B. Butler

Cryptography and Security · about 103 min · about 15,910 words · posted 2026-09-23 · arXiv non-exclusive licence · 11 figures, 2 tables

  • Accepted at NDSS
  • 91% prose
Abstract

The proliferation of audiovisual deepfakes has lowered the cost of fraud, impersonation, and misinformation, but their success ultimately depends on human perception. Detection requires integrating auditory and visual cues, yet security and privacy research has largely overlooked d/Deaf and hard-of-hearing (DHH) populations. We address this gap with an in-person, mixed-methods study of 80 participants: 31 hearing persons (HPs), 15 hard-of-hearing (HoH) participants, 17 d/Deaf participants, and 17 cochlear implant (CI) users. Each participant judged the authenticity of 30 clips, where manipulations spanned text-to-speech, voice conversion, lip-sync, or face-swap. DHH participants were less accurate than HPs overall (76.4% vs. 88.0%, p<.001), primarily because they more often classified authentic clips as manipulated (FPR: 29.7% vs. 11.2%). Differences depended strongly on the manipulated channel. For audio-only manipulations, HoH participants matched HPs (90.0% vs. 90.3%), followed by CI users (79.4%) and d/Deaf participants (41.2%). When clips contained an audiovisual manipulation, accuracy clustered between 84% and 87%, although performance still varied by manipulation method. Our work systematically characterizes how deepfakes affect DHH populations, highlighting the asymmetric risks audiovisual manipulations may pose to groups with different hearing abilities and the need for accessible, tailored defenses that support all users.

Theory and Algorithms

Complexity, data structures, logic, and proofs about computation.

CuACD: A Fully GPU-Resident Approximate Convex Decomposition

Ruoxi Shi, Xinyue Wei, Fanbo Xiang, Zexiang Xu, Hao Su

cs.CG · about 59 min · about 9,084 words · posted 2026-09-23 · CC BY 4.0 · 16 figures, 6 tables, 1 equations

  • 93% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
Abstract

Approximate convex decomposition (ACD) converts triangle meshes into small sets of convex parts and is a standard preprocessing step for physics simulation, collision detection, and large-scale robot learning. The majority of modern ACD methods produce high-quality decompositions through an expensive search over candidate cutting planes, with per-mesh runtimes of tens of seconds that force game pipelines into overnight bakes and keep articulated-object datasets on CPU clusters for days. Prior work has accelerated isolated stages, most recently VisACD's GPU-based visibility metric, yet the dominant costs -- search, mesh cutting, and convex hull construction -- have remained on the CPU because their natural decomposition into many small homogeneous phases trails off in a fading last wave at every kernel boundary, and the variable-sized output of each phase forces a host round trip simply to allocate the next launch's input. We address these obstacles by adopting the warp, rather than the thread or thread block, as the unit of algorithm design, an idea introduced in the graph-processing community for a different pathology and which we adapt here to fuse the many heterogeneous phases of a computational-geometry pipeline into single warp-resident kernels, paired with a device-side heap allocator that lets the buffers between fused phases be sized and allocated on the device. Building on this template, we present CuACD (CUDA ACD), the first fully GPU-resident ACD system, together with a suite of reusable GPU components, released as open-source standalone CUDA modules that drop into any search-based ACD pipeline. On the V-HACD benchmark, PartNet-Mobility, and an Objaverse subset, CuACD achieves more than an order of magnitude of speedup over CoACD at matched or better quality.

Practical and Space-Efficient LZ77 and LZ Pre-Compression via String Synchronizing Sets

Jonas Ellert, Lukas Nalbach

Data Structures and Algorithms · about 59 min · about 9,169 words · posted 2026-09-24 · arXiv non-exclusive licence · 6 figures, 4 tables, 9 equations

  • Accepted for publication
  • 76% prose
  • Code or project page linked
  • 17 pages
Abstract

The Lempel-Ziv (LZ77) factorization decomposes a text into the least possible number $z$ of phrases that each refer to an earlier occurrence. It is this phrase count, rather than the encoded size, that governs the size of LZ-based compressed indexes, and computing a factorization with few phrases is a time and space bottleneck in their construction. In practice, computing LZ77 quickly has so far required building a suffix array. Ellert [SPIRE 2023] gave algorithms that compute the exact LZ77 factorization, and a 3-approximation of it, in sublinear working space. They have remained unimplemented, because two of their components resist a direct implementation: a lookup table that degenerates to patterns of length at most two for realistic inputs, and an orthogonal range reporting data structure that is impractical. We replace both, fine-tune every remaining stage, and obtain the first practical implementation, which runs in space close to the text rather than to the suffix array. On one thread, our 3-approximation factorizes 12-19x faster than the classical LPF algorithm while using 14x less memory; on 32 threads, even our exact algorithm is 1.4--2.9x faster than parallel LPF, at 9x less memory. In practice the approximation ratio stays far below 3. As a side result, passing only its perfect phrases to a downstream compressor yields a precompressor that is on par with the state of the art [Dinklage, SEA 2026] in compression ratio, and better in memory consumption and parallel throughput.

A New Gap Sequence for Shellsort: RL-Driven Algorithm Discovery Beyond $N^{4/3}$

Bo Liu

cs.CC · about 49 min · about 7,543 words · posted 2026-09-24 · CC BY 4.0 · 2 tables, 129 equations

  • Filed in 3 fields
  • 85% prose
  • Openly licensed
  • 25 pages
Abstract

Choosing Shellsort gaps is a well-known open problem. For over sixty years, successful sequences have relied on human-designed formulas, numerical searches, or number-theoretic constructions. Although stronger general bounds exist for dense or mainly theoretical families, the worst-case upper bound for a short, sparse, and practically competitive construction has not advanced beyond $N^{4/3}$ for decades. We ask whether the sequence itself can instead be learned from execution. We present an RL-driven, self-supervised system that searches over executable gap generators. Every proposal is valid by construction, and executed candidates return exact comparison and move counts; no classical sequence is used as a target. Across five independent searches, the system discovers a common rational-geometric family. A second self-supervised stage tunes only a finite prefix, producing the practical sequence $1,3,8,20,47,116,300,585,1416,3303,\ldots$. Once frozen, it obtains the lowest equal-task average operation count among seven classical baselines on 25 large tasks with $10^7<N\leq 10^8$. We complete the learned tail without changing its practical behavior: only beyond $10^{1000}$, a zero-density set of unit companions $h_s+1$ removes the remaining congruence barriers. The resulting sparse sequence has matching polynomial upper and lower exponents, up to polylogarithmic factors: $Ω(N^{1.024296451657\ldots}) \leq T(N) \leq O(N^{1.024296451657\ldots}\operatorname{polylog} N)$. The lower bound follows from Zang's recent theorem for rational-geometric sequences; our contribution is the matching upper bound. Thus one exact sequence connects self-supervised discovery, large-scale practical performance, and a substantial step below the classical $N^{4/3}$ bound for sparse practical Shellsort sequences.

A Proof of the Most Informative Boolean Function Conjecture

Zijie Chen, Amin Gohari, Adel Javanmard, Honghao Lin, Vahab Mirrokni, Chandra Nair, David P. Woodruff

Data Structures and Algorithms · about 438 min · about 67,965 words · posted 2026-09-21 · CC BY 4.0 · 12 tables, 1644 equations

  • Filed in 3 fields
  • 79% prose
  • Openly licensed
Abstract

Let $X$ be uniform on $\{-1,1\}^n$, let $Y$ be obtained by passing its coordinates independently through a binary symmetric channel with crossover probability $p$, and let $g:\{-1,1\}^n\to\{0,1\}$ be a Boolean function. We give a computer-assisted proof of the Courtade--Kumar conjecture $I(g(X);Y)\le1-H_2(p)$, where $H_2$ is binary entropy, with equality attained by dictator functions. The present work builds on the differential-equation method, itself a limiting form of the auxiliary-receiver approach in network information theory using a continuum of degraded receivers. The proof proceeds from a local inequality to a dimension-independent bound on entropy production. Differentiation along the Boolean noise semigroup expresses entropy production as an average of edge costs. The key estimate is therefore an unrestricted Bellman inequality with two mean constraints and two entropy constraints, allowing arbitrary couplings of the edge variables. This paper and its supplement provide the proofs and computational verification records. The document is lengthy because it is designed to be entirely self-contained, deriving all proofs from first principles and reproducing the proofs of cited results. The supplementary material supporting the computer-assisted parts of the proof are available online.

Sensing Assisted Satellite Backhaul with FBL UL and Broadcast DL for Massive IoT

Tijana Devaja, Milica Petkovic, Israel Leyva-Mayorga, Dejan Vukobratovic, Cedomir Stefanovic

cs.IT · about 24 min · about 3,744 words · posted 2026-09-23 · arXiv non-exclusive licence · 4 figures, 29 equations

  • Has a DOI
  • 90% prose
  • Filed in 2 fields
Abstract

Massive Internet of Things (IoT) networks operate with short packets whose reliability is limited by finite block- length (FBL) effects, while remote deployments increasingly rely on Low Earth Orbit (LEO) satellites for backhaul connectivity that is sensitive to atmospheric attenuation. In this paper, we pro- pose a unified end-to-end framework for satellite-assisted massive IoT networks that jointly models uplink FBL random access, sensing assisted satellite backhaul, and worst user broadcast downlink transmission. Uplink reliability is characterized using stochastic geometry, while atmospheric sensing and conservative SNR margins enable FBL-safe backhaul adaptation. Numerical results reveal an optimal uplink access probability due to the tradeoff between spatial reuse and FBL reliability, and show that sensing assisted backhaul margins significantly improve robustness against attenuation uncertainty.

Mathematics

Analysis, algebra, geometry, probability, and number theory.

Vanishing-noise asymptotics for Donsker-Varadhan rate functions on the circle

Milan Koresski

Probability · about 72 min · about 11,146 words · posted 2026-09-24 · CC BY 4.0 · 1 tables, 249 equations

  • Published in Electronic Journal of Differential Equations
  • Has a DOI
  • 75% prose
  • Openly licensed
Abstract

We study the vanishing-noise limit of the rate function for the Donsker-Varadhan large deviation principle for one-dimensional diffusion processes on a circle. As is well known, the rate function can be represented either as the Legendre transform of the principal eigenvalue of the perturbed infinitesimal generator or by a variational formula. We analyze the asymptotic behavior of the principal eigenvalue as the parameter in front of the noise goes to zero and compare the Legendre transform of the limit with the expression obtained as the limit of the variational representation. We prove, in particular, that the resulting expressions do not always coincide, leading to continuity and discontinuity phenomena in infinite-dimensional functional spaces. Moreover, we use the previous analysis to pass to the limit in the LDP, using the notion of Γ-convergence.

Auditing Bayesian Graph Alignment: Diagnostic Comparisons and Reference Failure

Melika Gorgi, Kourosh Mirsohi

stat.AP · about 52 min · about 8,013 words · posted 2026-09-19 · CC BY 4.0 · 4 figures, 9 tables, 11 equations

  • 91% prose
  • Filed in 4 fields
  • Code or project page linked
  • Openly licensed
  • 19 pages
Abstract

Bayesian graph alignment estimates correspondence probabilities, but convergence of an alignment-score trace need not imply accurate correspondence marginals. We audit this gap on 240 new exact graph pairs from four source families, 240 larger pairs with 20-100 vertices, and a separate 60-case exact implementation check. Under an explicit edge-flip likelihood, we compare three samplers and score, marginal, indicator, categorical, and classifier-based diagnostics. Marginal disagreement improves error discrimination over score R-hat for the exact informed sampler, but its improvement for vanilla local sampling is uncertain. Assignment-based R* and short indicator panels are competitive; no diagnostic dominates across samplers and endpoints. At larger sizes, diagnostics predict subsequent marginal changes, not posterior error, and classification performance depends on the drift threshold. Disjoint-window and held-out-chain checks attenuate but preserve positive associations. Only 22 of 240 original reference sets pass an agreement screen. On forty failure-selected cases, eightfold SMC particle escalation does not resolve disagreement, whereas additional rejuvenation helps. Longer informed runs remain unstable. An elementary feasible-alignment bound demonstrates severely unrepresentative SMC and informed-chain scores in concentrated 100-vertex cases, independently of approximate reference consensus. We also exhibit common-start chains with near-zero disagreement despite exact marginal error near .967. These results support assignment-sensitive auditing while identifying limits of finite budgets, diagnostic rankings, and reference agreement as evidence of accuracy.

Duality for matrix space questions

Yuval Wigderson

math.RA · about 49 min · about 7,548 words · posted 2026-09-24 · arXiv non-exclusive licence · 14 equations

  • Accepted for publication
  • 79% prose
  • Filed in 2 fields
  • 15 pages
Abstract

We present a new proof of a classical theorem of Dieudonné: if a linear space of $n\times n$ matrices consists entirely of singular matrices, then its dimension is at most $n^2-n$. Our proof is based on a surprising ``duality'' argument: we prove this universal upper bound by exhibiting a single matrix space that serves as a lower bound for a related problem. Interestingly, this approach only works for certain fields, but we use model-theoretic arguments to obtain the same result for all fields. We hope that this approach can be generalized to provide new duality-based proofs of other classical theorems on matrix spaces, and give some preliminary results in this direction.

Asymptotic Balance and Structural Rigidity in the Riemann Zeta Function

Pedro Caceres

math.GM · posted 2026-09-22 · CC BY-NC-ND 4.0

  • Published in Journal of Theoretical Physics & Mathematics Research, May
  • Has a DOI
Abstract

We establish a structural rigidity principle for the nontrivial zeros of the Riemann zeta function by analyzing the asymptotic interaction between discrete Dirichlet oscillations and their continuous analytic envelope. The starting point is a renormalized discrepancy operator, the C-transformation, which isolates the finite structural difference between the Dirichlet series and its integral approximation. Applied to the kernel x^(-s), this operator yields a decomposition of the zeta function into three parts: an oscillatory Dirichlet component X_N(s), an explicit analytic growth envelope Y_N(s), and a polynomially decaying remainder R_N(s). We show that the vanishing condition zeta(s)=0 forces an asymptotic compatibility between the two dominant components. This relation is formalized in a Bridge Lemma, which proves that zeros require asymptotic equality of the squared magnitudes |X_N(s)|^2 and |Y_N(s)|^2. A detailed asymptotic analysis then reveals that the ratio of these magnitudes exhibits three distinct regimes depending on the real part sigma=Re(s): divergence for sigma>1/2, collapse for sigma<1/2, and exact balance for sigma=1/2. This incompatibility of growth regimes produces a rigidity mechanism: the asymptotic balance required by the zero condition can occur only on the critical line. Consequently, every nontrivial zero must satisfy Re(s)=1/2. The result provides a deterministic explanation for the location of the zeros, showing that the critical line emerges from an intrinsic structural constraint of the Dirichlet representation of the zeta function.

A structural proof of the Karpelevič theorem

Brecht Verbeken, Vincent Ginis

math.RA · about 90 min · about 13,914 words · posted 2026-09-23 · CC BY 4.0 · 3 figures, 188 equations

  • Filed in 3 fields
  • 77% prose
  • Openly licensed
  • 40 pages
Abstract

We give a self-contained proof of the Karpelevič theorem by reducing an extremal invariant polygon to a cyclic product with an exact real phase. A minimum branching count organizes the contacts, and face persistence makes a projective deformation applicable without separate tower-height cases. Convexity determines the sharp radius; explicit stochastic realizations and an independent Farey comparison identify the complete boundary. The resulting scalar equation also gives a uniform relative asymptotic for the radial deficit, including points arbitrarily close to Farey endpoints. It yields an $N^{-3}$ loss in badly approximable directions and a worst-direction loss of order $N^{-2}$ for optimal polygonal gauges.

Physics

Matter, fields, and the experiments that pin them down.

Impact of soft QCD effects over intrajet azimuthal anisotropies

Jesus Alberto V. Corral, A. Cota Rodriguez, J. A. Murillo Quijada

hep-ph · about 28 min · about 4,351 words · posted 2026-09-24 · CC BY 4.0 · 5 figures, 2 tables

  • Published in J. Phys. G: Nucl. Part. Phys
  • 94% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
  • 13 pages
Abstract

Observations of collective signatures within jets of particles have been recently reported by measurements at the Large Hadron Collider at CERN laboratory, providing insights on the minimum conditions required for forming a Quark Gluon Plasma state. A quantitative comparison with data measurements on intrajet azimuthal anisotropies and predictions from PYTHIA event generator soft QCD model parameter tunes: Monash, CP5, and QCD-scheme CR is presented. Energetic jets with transverse momentum over 550 GeV from proton-proton collisions at 13 TeV are reconstructed. Results from predictions using the standard E-scheme (ES) and jet axis choice are compared with those from the Winner-Take-All (WTA) frame. Significant differences are present between predictions from WTA and ES frames at the lowest and highest intrajet charged particles multiplicities ($N_{\mathrm{ch}}$), with the QCD-scheme CR tune showing the smallest variation between frames. Predictions for $v_2$ at the highest $N_{\mathrm{ch}}$ are consistent with the data measurements at a 2.3$σ$ uncertainty level. These results set new guidance towards the search for intrajet collective effects and understanding of nonperturbative QCD dynamics originated from a single parton.

Static Solitons in an Expanding Universe

Nagabhushana Prabhu

hep-th · about 88 min · about 13,625 words · posted 2026-09-22 · CC BY 4.0 · 10 figures, 224 equations

  • Published in Universe 12(4)
  • Has a DOI
  • Filed in 4 fields
  • 78% prose
  • Openly licensed
Abstract

We show, analytically, that a static sine-Gordon soliton cannot exist in 1 + 1 non-dynamical de Sitter spacetime if $α:= (m/H)^2 < 2$, where $m$ is the mass parameter of the sine-Gordon theory and $H$ is the Hubble constant. Conversely, we also show that static sine-Gordon solitons exist in 1 + 1 non-dynamical de Sitter spacetime if $α> 2$. The above threshold is explained---qualitatively and to within an O(1) factor---using a heuristic argument involving the interplay of tensile force in the Lorentzian sine-Gordon soliton and the tidal force in de Sitter spacetime. A similar heuristic argument, which remains to be confirmed analytically, also suggests the existence of a threshold, $ (m_V/H)^2 \sim O(1)$, below which the tidal forces are too strong to permit the existence of a static `t Hooft--Polyakov monopole in non-dynamical 3 + 1 de Sitter spacetime; $m_V$ is the mass of the vector boson. Linde has suggested that new inflation could have triggered secondary inflation at the core of a GUT (Grand Unified Theory) monopole even if the Hubble constant at or after the GUT phase transition was significantly smaller than the mass of the $X$ boson. We present a heuristic argument, which suggests that the $SO(3)$ `t Hooft--Polyakov monopole does not allow secondary inflation at its core when the inflationary background is weak. Based on the above, as yet analytically unconfirmed, heuristic argument for the $SO(3)$ `t Hooft--Polyakov monopole, we conjecture that secondary inflation at the core of a GUT monopole is infeasible.

Hyperfine Structure of $B$ and $D$ Mesons in a QCD-Inspired Potential Model

Krishna Kingkar Pathak

hep-ph · about 18 min · about 2,759 words · posted 2026-09-23 · CC BY 4.0 · 2 figures, 2 tables, 19 equations

  • Published in published in Eur. Phys. J. Plus
  • Has a DOI
  • 88% prose
  • Openly licensed
  • 8 pages
Abstract

We investigate the hyperfine structure of $B$ and $D$ mesons within a QCD-inspired potential model based on the Cornell ansatz. The conventional contact spin--spin term is regularized with a Gaussian smearing to remove the short-distance singularity, and analytic wavefunctions are obtained using the Dalgarno--Lewis perturbative method with the Coulomb part as parent. The numerical study has been extended to include explicit 2S hyperfine predictions and results for the $B_c$ system; these additions probe the stability of the potential parameter space (effective $α_s$, confinement strength and smearing width) for unequal-mass systems and radial excitations. We also present a short sensitivity study of the fixed effective coupling $α_s$ and discuss the physical interpretation of the smearing parameter $σ$. The combined analytic and phenomenological framework provides compact, testable benchmarks for upcoming spectroscopy measurements.

Anisotropy and energy distribution of leptons and photons in radiative relativistic Alfvénic turbulence

Peng Liu, Xiaochun Wei, Zheng Gong

physics.plasm-ph · about 24 min · about 3,765 words · posted 2026-09-24 · CC BY-NC-ND 4.0 · 4 figures, 12 equations

  • Published in Phys. Rev. D
  • Has a DOI
  • 88% prose
  • Filed in 2 fields
Abstract

The anisotropic evolution of relativistic particles in magnetically dominated Alfvénic turbulence is a fundamental process governing nonthermal emissions in high-energy astrophysical environments. In this work, we develop a theoretical framework by deriving scaling equations that characterize the pitch-angle dynamics of leptons and photons across both weak- and strong-radiative cooling regimes. Our model reveals a universal coupling between particle energy and angular distribution, arising from the interplay of field-aligned accelerations, perpendicular drift motions, and radiation reactions. The model can uniquely identify ``turning-point energies" that exhibit a nonlinear dependence on the local magnetic field and the energy-injection scale. The validity of this scaling model is confirmed through radiative particle-in-cell simulations. We show that the electron pitch-angle distribution fundamentally dictates photon emission characteristics, further revealing a pronounced statistical correlation between high-energy photon emission and turbulent vortices in the reconnection regions. By bridging the gap between small-scale kinetic interactions and broad-band spectral characteristics, this work provides a quantitative basis for interpreting the hardening of radiation spectra and complex polarization signatures in sources such as pulsar wind nebulae and gamma-ray bursts.

Plasma instability splits axion-photon conversion lines

Elizabeth A. Tolman

hep-ph · about 31 min · about 4,755 words · posted 2026-09-23 · arXiv non-exclusive licence · 4 figures, 2 tables, 63 equations

  • Accepted for publication
  • Has a DOI
  • Filed in 3 fields
  • 89% prose
  • 12 pages
Abstract

The axion coupling to electromagnetism may leave signatures of uncertain nature in astrophysical spectra; one is thought to be a single line centered at the axion frequency $ω= \sqrt{\left(m_a c^2/\hbar\right)^2 + c^2 k_a^2}$, with $m_a c^2/\hbar$ the axion Compton frequency and $\hbar k_a$ its momentum. If a parametric plasma instability is excited, this signature is transformed into a set of lines, which may be proportionally spaced and linearly polarized. A Crab pulsar signal at a frequency near recent cosmological predictions for the axion Compton frequency has some qualitative similarity to this signature, though this similarity is not evidence that the signal is caused by axions.

Space and Astronomy

Stars, galaxies, planets, and the instruments pointed at them.

VLTI/MATISSE observations of the hot dust around $β$ Pictoris: Observing faint objects with MATISSE

P. Priolet, J. -C. Augereau, J. Milli, A. Matter, B. Lopez, H. Beust, J. Varga, P. Boley, W. -C. Danchi, L. Foteini, T. Henning, M. Houllé, M. Letessier, F. Millour, J. Scigliuto, G. Weigelt, S. Wolf, O. Absil, J. -P. Berger, Y. -I. Bouarour, G. Bourdarot, D. Defrère, C. Desgrange, J. -B. Le Bouquin, D. Iglesias, T. A. Stuber, P. Berio, F. Bettonvil, P. Cruzalèbes, M. Heininger, J. W. Isbell, S. Lagarde, A. Meilland, R. Petrov, S. Robbe-Dubois

Earth and Planetary Astrophysics · about 79 min · about 12,226 words · posted 2026-09-24 · CC BY 4.0 · 17 figures, 7 tables, 17 equations

  • Published in Astronomy & Astrophysics, 713, A51
  • 93% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
Abstract

Context: Hot exozodiacal dust has been detected around approximately 20% of nearby main-sequence stars, indicating that it is a common feature of extrasolar planetary systems. However, its spatial distribution and grain properties remain poorly understood. Aims: We aim to show that the spatial distribution of hot dust around beta Pictoris, an iconic planetary system with two known planets and a population of exocomets, can be constrained through a detailed analysis of optical long-baseline interferometry data. Methods: We obtained L-band observations at approximately 3.5 microns of beta Pictoris with MATISSE at the VLTI. We developed a method to assess correlations in the visibility measurements by estimating the full data covariance matrix, and modeled the circumstellar emission with geometric brightness distributions. Results: We detect circumstellar emission around beta Pictoris consistent with hot exozodiacal dust. Modeling the emission with and without accounting for data correlations demonstrates their significant impact on the inferred dust properties. The best-fit model reveals a compact (approximately 0.05 au), highly inclined dust structure near the sublimation radius, misaligned by approximately 60 degrees on the sky with respect to the extended edge-on outer disk. It contributes approximately 4%-7.5% of the total flux at 3.4 microns and is composed of submicron-sized grains. The data are also compatible with an additional dust component near 1 au. Conclusions: For beta Pictoris, the two-decade-old paradigm placing hot exozodiacal dust near the sublimation radius and consisting of submicron-sized grains finds observational support in the detailed analysis of MATISSE data. The misalignment with the known debris disk further supports a link to exocometary activity.

Supermassive black hole binaries in the multi-messenger context of ground and spaceborne VLBI

B. Hudson, L. I. Gurvits, D. J. D'Orazio, C. Tiede, T. M. Eubanks, E. Mooij

High Energy Astrophysical Phenomena · about 71 min · about 11,066 words · posted 2026-09-08 · CC BY 4.0 · 10 figures, 2 tables, 38 equations

  • Accepted for publication
  • 92% prose
  • Filed in 2 fields
  • Openly licensed
  • 22 pages
Abstract

Evidence of a gravitational wave background suggests the existence of a population of sub-parsec supermassive black hole binaries (SMBHBs), with characteristic angular separations on the order of 1-10 $μ$as. Spaceborne extensions of Very Long Baseline Interferometry (VLBI) and the next generation ground arrays introduce the possibility of directly imaging these SMBHBs. In this work, a binary Spectral Energy Distribution (SED) model is used to predict the detectability of SMBHBs with ground and spaceborne VLBI. We consider the Black Hole Explorer (BHEX), a proposal for a spaceborne VLBI mission, as our primary case study. We explore the detectable SMBHB parameter space and identify distinguishable binary signatures that could exist in the visibility domain. We find that for a flux-density-limited sample, ground array observations are more effective at detecting a wider region of the binary parameter space, with $M_\mathrm{tot} \gtrsim 10^9$ solar mass systems detectable out to redshift, $z=0.075$ and beyond. Conversely, inclusion of a spaceborne element such as BHEX, offering finer angular resolution ($\sim6\,μ$as) and sampling of the (u,v) plane not limited by Earth rotation synthesis, will provide significant benefits in constraining binary properties, resulting in improvements in characterisation of the separation and position angle of SMBHBs by a factor of $\sim4$. Near-future ground and/or spaceborne VLBI may achieve the first direct observation of a SMBHB, contributing significantly to multi-messenger studies of such systems with pulsar timing arrays and observations across the electromagnetic spectrum.

Dark matter haloes from dwarf to massive galaxies: no systematic inner-density tension with ΛCDM hydrodynamical simulations

Pavel E. Mancera Piña, Justin I. Read, Jorge Sarrato-Alós, Claudia Muni

Astrophysics of Galaxies · about 80 min · about 12,429 words · posted 2026-09-21 · CC BY 4.0 · 13 figures, 16 equations

  • Accepted for publication
  • 92% prose
  • Filed in 2 fields
  • Openly licensed
  • 12 pages
Abstract

Two of the most prominent small-scale challenges to the cold dark matter (CDM) paradigm are the cusp-core and diversity-of-rotation-curves problems. The former concerns the shallow inner DM density profiles inferred for many galaxies compared with the cusps predicted by collisionless CDM, while the latter concerns the wider range of inner DM densities and rotation curve shapes inferred observationally than hydrodynamical simulations traditionally reproduce. Robust observational constraints on DM core sizes and halo densities are therefore essential for testing both the nature of DM and the impact of galaxy formation processes. We analyse the inner DM distribution of a curated sample of 48 gas-rich galaxies and 8 Milky Way gas-poor satellites, spanning 6 orders of magnitude in $M_\ast$. We find substantial scatter in DM core sizes and degrees of coreness, with both cuspy and cored haloes occurring over a broad $M_\ast$ range. The cores are energetically consistent with stellar feedback, requiring modest supernova energy coupling efficiencies of order $0.1-1\%$. Comparisons with the NIHAO, FIRE-2, and EDGE simulations reveal broad agreement in the inner DM densities and logarithmic slopes of observed and simulated galaxies. The main residual differences concern the steep slopes of some massive simulated galaxies and differences in SHMRs. Using a rotation-curve diversity diagnostic from previous work, we find that extreme discrepancies with simulations are absent from our curated sample and largely attributable to uncertain kinematics or baryonic mass distributions. Within the scope of our analysis, we find no evidence of a systematic inner-density tension between our galaxy sample and current $Λ$CDM hydrodynamical simulations. Together with the modest energetic requirements for core formation, this substantially alleviates the cusp-core and diversity-of-rotation-curves problems.

Tomography analysis of the intermediate-luminosity Type Iax SN 2024pxl

Barnabás Barna, Mridweeka Singh, Lindsey A. Kwok, Saurabh W. Jha, R. Dastidar, Conor Larison, Alexei V. Filippenko, J. P. Anderson, Jennifer E. Andrews, Moira Andrews, G. C. Anupama, Prasiddha Arunachalam, Katie Auchettl, Dominik Bánhidi, K. Azalee Bostroem, Thomas G. Brink, Régis Cartier, Ping Chen, T. -W. Chen, Collin T. Christy, David A. Coulter, Sofia Covarrubias, Kyle W. Davis, Connor B. Dickinson, Yize Dong, Joseph Farah, Andreas Flörs, Ryan J. Foley, Noah Franz, Christoffer Fremling, Lluís Galbany, Anjasha Gangopadhyay, Aarna Garg, Elinor L. Gates, Or Graur, Mariusz Gromadzki, Daichi Hiramatsu, Emily Hoang, D. Andrew Howell, Brian Hsu, Joel Johansson, Arti Joshi, Lordrick A. Kahinga, Ravjit Kaur, Sahana Kumar, Piramon Kumnurdmanee, Hanindyo Kuncarayakti, Chang Liu, Keiichi Maeda, Kate Maguire, Bailey Martin, Curtis McCully, Darshana Mehta, Luca M. Menotti, Anne J. Metevier, A. A. Miller, Kuntal Misra, Erika Mochnács, T. E. Müller-Bravo, Megan Newsome, Estefania Padilla Gonzalez, Kishore C. Patra, Jeniveve Pearson, Anthony L. Piro, Abigail Polin, Aravind P. Ravi, Armin Rest, Nicolas Meza Retamal, O. M. Robinson, César Rojas-Bravo, Devendra K. Sahu, David J. Sand, Brian P. Schmidt, Steve Schulze, Michaela Schwab, Manisha Shrestha, Matthew R. Siebert, Sunil Simha, Nathan Smith, Jesper Sollerman, Shubham Srivastav, Bhagya M. Subrayan, Tamás Szalai, Kirsty Taggart, Rishabh Singh Teja, Jacco H. Terwel, Samaporn Tinyanont, Stefano Valenti, József Vinkó, Aya L. Westerling, J. Craig Wheeler, Yi Yang, WeiKang Zheng

High Energy Astrophysical Phenomena · about 55 min · about 8,502 words · posted 2026-09-23 · CC BY 4.0 · 7 figures, 4 tables, 1 equations

  • Accepted for publication
  • 97% prose
  • Filed in 2 fields
  • Openly licensed
  • 11 pages
Abstract

We present an abundance tomography analysis of SN 2024pxl, an intermediate luminosity Type Iax supernova ($M_{r}=-16.82 \pm 0.19$ mag), with the most-detailed follow-up in the Type Iax subclass to-date. As one of the few intermediate luminosity Type Iax objects, SN 2024pxl may link the two extremes of the peculiar thermonuclear supernova subclass. To test this hypothesis, we analyze its spectral evolution through the first 100 days after the explosion and aim to probe the structure of its ejecta. We conduct an abundance tomography analysis using synthetic spectra produced with the one dimensional radiative transfer code TARDIS. The fit of the spectral time series provides a radial scan of physical properties and probes the stratification of chemical elements throughout most of the SN ejecta. The observed spectral evolution is well fit with the final model, similar to the general predictions of the pure deflagration scenarios, but significant modifications are required in the density function of the inner ejecta and in the chemical profiles of the outermost regions. The constrained physical characteristics, such as the photospheric velocities and the time of maximum light, are also consistent with other SNe~Iax. Despite their small number, intermediate luminosity Type Iax SNe are not outliers in the subclass but demonstrate the continuous nature of SNe Iax through their luminosity range. Following this observation, we argue that all SNe~Iax share the same progenitor and explosion origin.

Metal-poor Brown Dwarf Kinematics from JWST NIRSpec Spectroscopy

Chih-Chun Hsu, Christopher A. Theissen, Adam J. Burgasser, Adam C. Schneider, Christian Aganze, Aaron M. Meisner, Jonathan Gagné, Nicolas Lodieu, Zenghua Zhang, Genaro Suárez, Eileen C. Gonzales, Jacqueline K. Faherty, Jason J. Wang, Stanimir Metchev, Dan Caselden, Michael C. Cushing, Roman Gerasimov

Solar and Stellar Astrophysics · about 54 min · about 8,421 words · posted 2026-09-23 · CC BY 4.0 · 5 figures, 6 tables

  • Accepted for publication
  • Filed in 3 fields
  • 89% prose
  • Openly licensed
  • 21 pages
Abstract

Galactic archaeology relies on stellar kinematics and chemical abundances to identify various stellar populations and associations. With JWST, Galactic archaeology of ancient metal-poor brown dwarfs is now possible through high-sensitivity, medium-resolution spectroscopy. We present the first metal-poor brown dwarf radial velocity (RV) survey using JWST/NIRSpec G395H spectra ($λ/Δλ\sim$ 3,000) for a sample of 23 LTY dwarfs across a wide range of temperatures and metallicities. We introduce a forward-modeling framework to measure robust RVs for brown dwarfs by focusing on the CO fundamental band at $\sim$4.5 $μ$m. By comparing to sources with existing high-resolution RV measurements, we demonstrate that G395H RVs can achieve a systematic uncertainty of 5 km s$^{-1}$, sufficient to examine their Galactic space motions. We identify kinematic members of the Milky Way's thin disk, thick disk, and halo populations in this sample. We also confirm WISE J155349.98$+$693355.2 as likely associated with the Gaia-Enceladus merger remnant, and 2MASS J05325346$+$8246465 is likely associated with the Thamnos stream. Our study systematically demonstrates that JWST G395H spectroscopy can provide robust RVs in addition to detailed chemical abundances, necessary for Galactic archaeology studies. Future discoveries and characterization of brown dwarfs associated with Galactic halo substructures and streams will enable a stringent test of stellar/substellar formation and evolutionary models for diverse metallicities.

Life Sciences

Genomes, neurons, populations, and the models of them.

Mathematical Modelling of Within-Host HIV Dynamics with Cytotoxic Immune Response and Antiretroviral Therapy

Maxim Polyakov, Yulia Chernikova

Populations and Evolution · about 47 min · about 7,300 words · posted 2026-09-24 · CC BY 4.0 · 7 figures, 2 tables, 58 equations

  • 94% prose
  • Filed in 3 fields
  • Openly licensed
Abstract

We develop and analyse a mechanistic ODE model of within-host HIV dynamics that includes uninfected CD4$^+$ T cells, latently and productively infected cells, free virions, and cytotoxic immune effectors. Antiretroviral therapy is described by two time-dependent efficacy functions that separately reduce new infections and virion production. We show that solutions remain non-negative and bounded, identify the infection-free and endemic equilibria, and derive the basic reproduction number together with the local stability condition for the infection-free state. We also obtain treatment-dependent suppression thresholds and an analytical estimate of when this threshold is crossed as treatment efficacy declines. Numerical simulations consider untreated infection, ART initiation, periodic variation in efficacy, and progressive loss of treatment effect. Without therapy, the model approaches a state of persistent infection. ART reduces viral load and promotes recovery of the CD4$^+$ T-cell population, while the latent reservoir persists under the parameter set considered. Periodic changes in treatment efficacy produce sustained forced oscillations. These results connect the analytical threshold conditions with the treatment-dependent dynamics of the model and provide a basis for future calibration, sensitivity analysis, uncertainty quantification, and extensions informed by clinical data.

Consistent determination of stability regimes in natural ecological communities from abundance time series

Alberto Megías, Vicente J. Ontiveros, David Alonso, José A. Capitán

Populations and Evolution · about 45 min · about 6,924 words · posted 2026-09-24 · arXiv non-exclusive licence · 4 figures, 1 tables, 9 equations

  • 91% prose
  • Filed in 3 fields
  • 27 pages
Abstract

The stability of an ecological community is conventionally defined through species interactions, which quantify how species affect one another. Interaction strengths are notoriously difficult to measure in species-rich assemblages. Long-term monitoring of species-rich communities, however, provides species abundance time series, increasingly available across habitats and taxa but not yet connected to the stability properties of the communities they describe. Here we develop a statistical framework that infers stability regimes in large ecological communities directly from abundance time series. We study stochastic Generalized Lotka--Volterra dynamics with random interactions and environmental fluctuations using dynamical mean-field theory, reducing the multispecies system to an effective stochastic process for a representative species. The theory predicts three stability regimes (stable coexistence, intermittent dynamics close to extinction, and unbounded growth) separated by analytical boundaries, and shows that environmental stochasticity systematically destabilizes coexistence by promoting intermittent low-abundance dynamics. The resulting steady-state species abundance distribution is a Gamma law that ties the dynamical phases to the variability-based stability metrics used in empirical studies. Recasting the effective dynamics as a multivariate regression model, we infer interaction statistics, environmental variability and the characteristic timescale of the dynamics from community data, without reconstructing the interaction network. Applied to natural communities spanning a broad range of habitats and taxa, the method resolves contrasting stability regimes and yields quantitative estimates of species extinction risk.

PocketVE: Stable and Property-Guided Structure-Based Drug Design with Variance-Exploding Diffusion

Peining Zhang, Jinbo Bi

q-bio.BM · about 56 min · about 8,696 words · posted 2026-09-08 · CC BY 4.0 · 9 figures, 17 tables, 42 equations

  • 93% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Protein-conditioned 3D molecule generation is a central challenge in structure-based drug design, requiring a balance between pocket compatibility, molecular properties, and physical geometry. We propose \textbf{PocketVE}, a protein-pocket-conditioned variance-exploding (VE) diffusion framework that couples stable coordinate denoising with inference-time property guidance. Specifically, PocketVE combines an EDM-style training and sampling setup for 3D denoising, classifier-free guidance for multi-property steering without external property classifiers, and adaptive protein perturbation as a training-time pocket regularizer. Evaluated on CrossDocked2020 under the GenBench3D protocol, PocketVE improves Valid$_{3\text{D}}$ from 58.6 to 80.6 and reduces strain energy from 457.4 to 127.9 relative to its TAGMol architectural baseline, while retaining competitive docking and molecular-property scores under moderate guidance. A guidance-scale study shows that moderate guidance gives a favorable balance between target-related objectives and geometric quality, whereas stronger guidance can degrade geometry and distributional fidelity. Pocket-permutation and PoseCheck diagnostics further support pocket-specific spatial compatibility with reduced steric conflicts. Overall, the results suggest that geometric stability and inference-time property guidance should be considered as coupled design objectives.

ProteoEM: probabilistic protein abundance estimation from iterative affinity traces

Narayanan Raghupathy

q-bio.QM · about 56 min · about 8,636 words · posted 2026-09-24 · CC BY 4.0 · 7 figures, 2 tables, 20 equations

  • 93% prose
  • Filed in 2 fields
  • Openly licensed
Abstract

Single-molecule affinity mapping enables molecular-level measurement of proteins and proteoforms, but imperfect and nonspecific probe binding makes individual affinity traces compatible with multiple molecular identities. Accurate abundance estimation therefore requires apportionment of ambiguous traces by weight rather than assignment to a single candidate. We developed ProteoEM, an expectation-maximization framework for weighted proteoform quantification, inspired by transcript abundance estimation methods for RNA sequencing and released as an open-source Python package. ProteoEM evaluates each molecule against every candidate using fixed, pre-calibrated probe-response rates held separate from the abundance estimate, while retaining the full likelihood of the observed affinity features. The framework estimates proteoform abundances, reports indistinguishable proteoforms as groups when measurements cannot separate them, and accounts for differential observation yields to distinguish the composition of observed molecules from that of the source sample. In simulations, ProteoEM accurately recovered the underlying molecular composition where approaches that reduce each trace to a hard yes/no call introduced substantial errors. ProteoEM's performance was insensitive to a moderate, uniform calibration error but was biased by informative missing data and by proteoforms absent from the reference. When observation yields were known, it also recovered source-sample composition from observed molecular counts. ProteoEM provides an open-source, reproducible framework for quantitative analysis of single-molecule affinity measurements, and these results motivate validation on experimental molecule-level data.

Predator self limitation controls pattern formation in a predator prey system with additional food: a Turing Hopf analysis

Anushree Hazra, Aniket Banerjee, Debaldev Janaa

Populations and Evolution · about 43 min · about 6,732 words · posted 2026-09-24 · CC BY 4.0 · 9 figures, 99 equations

  • 83% prose
  • Openly licensed
  • 24 pages
Abstract

Supplying a released predator with additional, non reproducing food is a standard lever in augmentative biological control, with a known drawback with nothing limiting the predators own numbers, the extra food lets its population grow without bound. Competition among the predators supplies the missing brake. Howthis self limitation reshapes the spatial arrangement of the two species has not been asked. We address it with a reaction diffusion model of a logistically growing prey and a predator feeding through a Holling type II response that also draws on additional food , the predators competing among themselves at strength. In the well mixed setting we locate the Hopf bifurcation of the coexistence state exactly and show the cycle born there is stable, so weak competition gives boom bust oscillations, not runaway growth. Allowing movement, we obtain the diffusion driven Turing threshold at which the uniform state breaks into stationary patches of high and low density, and find the uniform oscillation stable as it appears. With prey mobility and competition strength as control parameters, the pattern forming and oscillatory instabilities meet at a single point, where we compute the dynamics. Simulations confirm the sequence weak competition gives a wholefield oscillation, stronger competition with faster prey spread gives fixed patterns, and near the crossover the two combine into patterns that pulse in time. Predator self competition therefore sets the spatial structure of the community, which is what matters when additional food is used to steer a control agent in the field.

People and Economies

Markets, institutions, and computing where it meets society.

Fair Feed Ranking for Participatory Budgeting

Carina I. Hausladen

cs.CY · about 32 min · about 4,899 words · posted 2026-09-24 · CC BY 4.0 · 2 figures, 2 tables, 2 equations

  • Published in International Conference on Information Technology for Social Good
  • 92% prose
  • Has a DOI
  • Filed in 2 fields
  • Openly licensed
  • 8 pages
Abstract

In large-scale participatory budgeting, citizens cannot inspect the full proposal pool, so the order in which proposals are shown becomes a form of agenda-setting power. We argue that fair exposure should therefore be treated as a democratic-design goal. We study Consul Democracy, a widely deployed open-source digital-democracy platform, and show that its proposal feeds are typically ordered by popularity, recency, or comment activity. Building on this diagnosis, we propose FairFeed, a feed-ranking design for PB that uses transparently declared preferences, boosts under-exposed proposals, and admits a rate-limited reject channel for crowd-sourced vetting. We evaluate the design in a simulation anchored in Munich's 2025 PB process and compare it with random, newest, and most-commented feeds. In this simulation, FairFeed broadens proposal discovery, distributes visibility more evenly across the eligible pool, increases cross-cutting support, and improves resistance to manipulation relative to comment-based ranking. We conclude by outlining the human-subjects evaluation needed to test whether onboarding can recover voter preferences accurately enough for deployment in practice.

Deep-learning-aided dismantling of interdependent networks

Weiwei Gu, Chen Yang, Lei Li, Jinqiang Hou, Filippo Radicchi

cs.SI · about 62 min · about 9,594 words · posted 2026-09-24 · arXiv non-exclusive licence · 10 figures, 13 tables, 16 equations

  • Published in Nature Machine Intelligence 7, 1266-1277
  • 94% prose
  • Has a DOI
  • 32 pages
Abstract

Identifying the minimal set of nodes whose removal breaks a complex network apart, also referred as the network dismantling problem, is a highly non-trivial task with applications in multiple domains. Whereas network dismantling has been extensively studied over the past decade, research has primarily focused on the formulations of the optimization problem for single-layer networks, neglecting that many, if not all, real networks display multiple layers of interdependent interactions. In such networks, the optimization problem is fundamentally different as the effect of removing nodes propagates within and across layers in a way that can not be predicted using a single-layer perspective. Here, we propose a dismantling algorithm named MultiDismantler, which leverages multiplex network representation and deep reinforcement learning to optimally dismantle multi-layer interdependent networks. MultiDismantler is trained on small synthetic multiplex graphs; when applied to large, real and synthetic networks, it displays exceptional dismantling performance, clearly outperforming all existing methods that rely on a single-layer approach to network dismantling. We show that MultiDismantler is effective in guiding strategies for the containment of diseases in social networks characterized by multiple layers of social interactions. Also, we show that MultiDismantler is useful in the design of protocols aimed at delaying the onset of cascading failures in interdependent critical infrastructures.

How People Use ChatGPT in Australia: A WildChat Analysis

Ying Ma, Katy Gero, Clément Canonne, Craig Jin, Kanchana Thilakarathna

Human-Computer Interaction · about 62 min · about 9,608 words · posted 2026-09-24 · CC BY 4.0 · 11 figures, 2 tables

  • Published in Australasian Conference on Human-Computer Interaction
  • 100% prose
  • Has a DOI
  • Openly licensed
Abstract

Generative AI chatbots are increasingly embedded in everyday life, yet most large-scale studies describe global patterns. This paper presents an Australia-focused analysis of WildChat, a public dataset of real-world ChatGPT interaction logs. Using descriptive analysis and a multi-layer classification scheme, we analysed 37,845 conversations identified as Australian, examining language diversity, work relevance, interaction intent, topic distribution, turn-taking, temporal change, work activities, and Australia-related domains. Our findings show that the Australian subset is strongly action-oriented and comparatively work-oriented, with most interactions classified as doing and a majority of conversations classified as work-related. The dataset also shows multilingual use and a growing presence of self-expression over time. Australia-related conversations frequently invoke local institutions, laws, regulators, education systems, companies, cultural references, and public services. Finally, we outline implications for future research, including local AI evaluation, multilingual participation, context-aware design, and safeguards for everyday high-stakes domains.

Do Two On-Chain Observation Pipelines See the Same Tokens? Cross-Pipeline Coverage on the Solana pump.fun Launchpad

Arati Uday Kamat

q-fin.TR · about 44 min · about 6,819 words · posted 2026-09-23 · CC BY 4.0 · 1 figures, 4 tables

  • 100% prose
  • Has a DOI
  • Filed in 3 fields
  • Openly licensed
  • 15 pages
Abstract

On-chain studies of memecoin launchpads usually rely on one data-collection pipeline, yet whether differently configured pipelines observe the same tokens is rarely measured. This paper compares the output mint sets of two separately configured pipelines from one research programme on the Solana pump.fun launchpad: a cohort-detection pipeline that flags coordinated early-buyer wallets, and a rejection-filtering pipeline that logs a trader-side observer's pre-trade filter decisions. Two consecutive, non-overlapping windows are analysed (v1: June 2026; v2: June-July 2026); in each, the rejection data are restricted to the interval spanned by the cohort detections under four timestamp rules. Only raw counts, observed proportions and Jaccard/Dice indices are reported. In v2, where the rejection stream covers the whole 17.5-day window, the cohort set contains 623 mints and the rejection set 1,742, with 5 overlapping mints (0.803% of cohort; 0.287% of rejection). In v1 a collection gap means the rejection stream covers only the final 14.25 hours (4.4%) of the 13.4-day cohort window; the 20,162 cohort and 53 rejection mints share 1 mint, and within the covered interval none, a count too small to be informative. Both windows show nearly disjoint outputs, agreeing in direction but not in magnitude. Collector configuration, not only market behaviour, therefore shapes which tokens an on-chain study observes, and the paper proposes reporting cross-collector overlap and collector coverage as a routine check. Data and a script that re-derives every number are openly available.

OBLIQ-IR: Training a Dense Retriever for Oblique Queries

Mahmoud Abdalla, Abdelrahman Abdallah, Shaimaa Sedek, Adam Jatowt

Information Retrieval · about 58 min · about 9,001 words · posted 2026-09-21 · CC BY 4.0 · 15 figures, 18 tables, 8 equations

  • Accepted at EMNLP
  • 96% prose
  • Openly licensed
Abstract

Oblique retrieval, as exemplified by OBLIQ-Bench, asks a retriever to find documents whose relevance is determined by a latent attribute (an implicit stance, an analogous reasoning technique, an authorial fingerprint, or a vague tip-of-the-tongue recollection) that has little or no surface expression in the document. State-of-the-art dense encoders and agentic search pipelines built around frontier language models exhibit a large first-stage bottleneck on these tasks, while the same language models reliably verify relevance when shown candidates. We address this with OBLIQ-IR, a single-vector dense retriever whose training mixture combines per-mechanism synthetic queries with a new form of cross-model supervision: kNN-graph distillation from a frozen authorship encoder, which transfers a style-versus-topic inductive bias into the student. A 3B retriever fine-tuned reaches 0.211 NDCG@10 on Writing-Style, 0.171 on Math, 0.177 on Twitter, and 0.281 on Congress, improving over the GPT-5.2 Multi-Hop Agent by \xr{0.010 to 0.150} NDCG@10 and over Gemini-2-Embedding by 0.027 to 0.222 NDCG@10 on every reported task. The code, data and checkpoints are available https://github.com/DataScienceUIBK/obliq-ir

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