This paper analyzes deep transformer expressiveness using bounded-depth grammars. It constructs transformers with positional attention where model depth scales linearly with grammar depth, and neuron count grows quadratically with production rules. The results support the linear representation hypothesis by showing these models can encode abstract grammatical states in low-dimensional, linearly separable subspaces.
Concatenating LLM-generated features to graph neural networks systematically reduces accuracy on homophilous benchmarks, with PubMed accuracy dropping by -17.0 ± 0.3 pp. This degradation is linked to LLM-alone discriminability (Delta_sig), which correlates strongly with concatenation cost (r² = 0.38) and shows a power law relationship with feature dimension and node count (r² = 0.97), particularly in low-Delta_sig, low-node scenarios.
Pruned large language models often pass multiple-choice tests but fail to generate correct answers in open-ended responses. This 'benchmark illusion' shows that answers are not erased but demoted, reappearing only with advanced generation techniques like beam search or sampling. Standard benchmarks overstate the practical usability of compressed models, highlighting a critical evaluation blind spot.
OPD-Evolver introduces a slow-fast co-evolution framework that enables agents to select, act on, and reuse experience through on-policy self-distillation. It outperforms existing memory and training-based methods by up to 11.5% and 5.8% respectively, and demonstrates capability to challenge large-scale models like Qwen3.5-397B-A17B and Step-3.5-Flash.
A new framework uses prompt perturbation to identify and filter structurally inconsistent pairwise comparisons in large language model evaluations. By incorporating graph-level consistency checks before ranking aggregation, the method reduces cyclic preferences and improves the reliability of LLM rankings.
SkillMigrator learns reusable web skills by matching layout structures instead of specific element references. It stores each skill as a transferable interaction pattern (TIP) with a structural sketch, enabling efficient skill reuse across sites. Compared to state-of-the-art methods, it reduces average LLM-action counts by 8-10% on WebArena and Mind2Web at matched success rates.
MambaCount introduces a spatial sparse state space duality block to enable efficient text-guided open-vocabulary object counting. It addresses causal modeling limitations and high entropy in spatial token responses, achieving state-of-the-art results on FSC-147 with a test MAE of 12.23 while maintaining linear complexity.
EnvRL introduces a framework that enhances agentic reinforcement learning by incorporating environment dynamics through state prediction and inverse dynamics objectives. It achieves significant gains in success rates on long-horizon benchmarks, improving Qwen-2.5-1.5B-Instruct performance from 72.8% to 77.4% on ALFWorld and from 56.8% to 67.0% on WebShop when trained with GRPO.
The LLM-as-Environment-Engineer framework uses LLMs to automatically redesign training environments in reinforcement learning by analyzing failure trajectories and contextual data. On the MAPF-FrozenLake testbed, it outperforms larger proprietary LLMs and fixed-environment baselines, with Qwen3-4B achieving the strongest aggregate performance. Analysis shows that failure evidence and preserved working configurations are key, and the current RL checkpoint performs better than the base model as an environment engineer.
SwiftTrans addresses runtime efficiency gaps in LLM-based code translation by introducing Multi-Perspective Exploration and Difference-Aware Selection. The framework extends CodeNet, F2SBench, and introduces SwiftBench to evaluate runtime performance, showing consistent improvements in both correctness and efficiency across benchmarks.
SuCo introduces Minimal Sufficient CoT (MSC) as the shortest reasoning prefix adequate for correct answers. It employs a two-stage training framework—MSC-Aligned Fine-Tuning and Sufficiency-Aware Policy Optimization—to reduce reasoning length while maintaining or improving accuracy across math, code, and science tasks.
LLMs can detect cultural cues and recall cultural conventions, but often fail to adapt responses accordingly. Their responses remain biased toward their native culture unless explicitly prompted to apply cultural context sequentially.
A causal audit shows that text-only models match multimodal models in chest radiography accuracy. Across nine systems, a text-only model performs within 5.7 points of the best multimodal model, and a 119-billion-parameter model is indistinguishable from a 7-billion-parameter text-only baseline. Grounding audits, not accuracy, should determine clinical deployment.
EComAgentBench introduces a benchmark of 662 real Amazon tasks that scatter shopper requirements across query, profile, and clarification. Agents must uncover hidden intent, verify candidates with evidence, and commit to a product within 100 tool calls, with typed rubrics attributing failures to specific requirement sources. Evaluation shows even top models achieve only 57.1% accuracy, and rubric satisfaction drops when intent is hidden.
A system using AI to simulate virtual patients provides turn-by-turn feedback on Acceptance and Commitment Therapy practices. GPT-4o-mini achieved the lowest mean absolute error in matching human supervisor ratings, showing strong agreement in ACT fidelity. The tool supports therapist practice through realistic, low-risk interactions and immediate feedback.
AI-rewritten radiology reports show significant information loss, with EHR summarization eroding 51.4% of clinical entities and 43.7% of hedging language. Despite preserving image-text alignment, standardized and teaching case tasks reduce cross-modal alignment by 14.9-16.5%, six to seven times more than EHR summarization. The study finds no preferential degradation of rare pathologies and identifies rewriting task type as the key driver of degradation, not clinical content.
DIFE evaluates backdoored CLIP checkpoints across different deployment interfaces, revealing that native success does not guarantee safety in reuse. The framework shows text-side poisoning enables adversarial exposure in retrieval, reranking, and selection tasks, while visual-only use remains largely unaffected. BadTextTower is introduced to generate strong text-conditioned exposure without compromising visual performance.
The wav2vec2.0 model shows no evidence of perceptual compensation for Mandarin tones in embedding similarities. Probing classifiers reveal limited compensation and fail to match human performance on isolated syllables, suggesting supervised training is needed for phonological regularity abstraction.
A new framework automates prompt refinement for LLM agents by splitting the observation-to-action pipeline into goal-conditioned and action selection modules. It uses an LLM-driven evolutionary loop to iteratively improve prompts based on environment feedback, achieving up to 72.5% success on PutNext where prior agents failed, without model fine-tuning.
Dynamic Rollout Editing (DRE) addresses overthinking in RL-trained reasoning models by modifying successful trajectories post-answer emergence. DRE preserves the correct reasoning prefix while editing unnecessary continuation, weakening the credit assigned to redundant thinking without penalizing valid reasoning. Experiments across diverse tasks demonstrate its effectiveness in reducing overthinking.