Research

Digests of notable academic papers, primarily from arXiv

212 articles · page 3 of 5

RL for Agents

Shared-prefix training accelerates reinforcement learning for hybrid-attention agents

Meng et al. introduce HARTS, a training system that compresses shared prefixes in agentic reinforcement-learning rollout trees and schedules the remaining work across microbatches and data-parallel replicas. On rollouts generated from SWE-bench tasks, it delivered 4.81–4.87× speedups for forward, backward, and gradient computation while maintaining numerical and early-training behavior close to trajectory-wise training.

1 Sept 2026
Safety & Evals

MLLMs fail to sustain goal-directed navigation in real-scale 3D city

The authors introduce UrbanGround, a sandbox built from 3D geospatial data of Hong Kong, to test whether multimodal large language models (MLLMs) can turn local visual perception into sustained navigation. They find that while agents show useful abilities in short-range spatial reasoning and scene recognition, they fail at orientation, pedestrian-aware movement, and correcting accumulated errors over extended exploration.

30 Aug 2026
AI & ML

Learned sepsis score tracks hourly severity without hourly outcome labels

The authors trained a 0–10 sepsis severity index from 43 routinely charted variables collected over 72 hours, using treatment-level mortality to rank trajectories rather than assigning mortality labels to every hour. In held-out testing, the score provided hourly prognostic information, correlated with changes in lactate and other physiological measures, and showed partial transfer between hospital systems.

30 Aug 2026
Safety & Evals

Agent safety requires persistent state across autonomous loop iterations

Wu and colleagues analyze autonomous agents that repeatedly plan, use tools, verify results and retain operational state, even as their safety monitors reset. They establish a formal separation showing that persistent safety state can detect cross-iteration attacks invisible to any trajectory-scoped monitor, and propose LoopHarness to limit irreversible unauthorized actions independently of the loop horizon.

29 Aug 2026
Tools & MCP

Structured software interfaces outperform screenshot-and-click control for AI agents

Xie and Chen replace visual GUI control with an agent-facing layer that represents application state as JSON and exposes semantically meaningful, code-executable actions. On 380 single- and multi-application tasks, closed models using ASIL achieved more than 80% strict success while averaging fewer than five actions per task, far exceeding screenshot-based control under the tested conditions.

29 Aug 2026
Memory & Planning

Dual-brain memory keeps real-time speech agents accurate and emotionally aware

VoiceMem is a dual-stream memory architecture for duplex speech language models, pairing a factual left brain for personal information with an emotional right brain for affect and persona. The authors show that top-5 retrieval beats Mem0 at top-200 by nearly 30 points, and that retrieval completes in 134 ms, within voice-activity-detection latency. The result is a practical memory foundation for real-time, personalized, emotionally aware spoken interaction.

28 Aug 2026
AI & ML

Self-evolving loop synthesizes high-quality multimodal training data

The authors present VISA, an agentic framework that reformulates multimodal instruction synthesis as a self-evolving loop. VISA iteratively generates diverse and challenging instruction-following samples, using verifier signals and target-model failure profiles to guide subsequent rounds. The method consistently improves multimodal instruction following on MM-IFEval while maintaining general multimodal capability across seven benchmarks.

28 Aug 2026
Memory & Planning

Sliding reasoning windows make long test-time scaling 3x faster

Muennighoff et al. observe that during long reasoning traces, most intermediate tokens lose importance as the model continues. They propose Prefix Sliding, which keeps only the instruction prefix and a recent window of tokens, discarding the rest to cap memory usage. Applied without training to existing models, it achieves up to 3x speedup with no performance loss; training with it enables reasoning traces beyond 100,000 tokens.

28 Aug 2026
RL for Agents

Contrastive branch training improves credit assignment for tool-using language models

Wang et al. introduce Contrastive Branch Policy Optimization (CBPO), a reinforcement-learning method that separates where to sample alternative continuations from how to assign credit to tokens. Across ten mathematical-reasoning and knowledge-search benchmarks, the authors report the highest macro-average accuracy among the evaluated policy-optimization and branch-based methods at two model scales.

27 Aug 2026
Safety & Evals

Bayesian framework exposes hidden differences among seemingly similar RAG systems

The authors evaluate 27 retrieval-augmented generation configurations using a Bayesian model structured around how information and errors flow through a RAG pipeline. They show that systems with similar aggregate scores can behave differently after successful versus failed retrieval, and that labeling retrieval success is especially valuable for estimating whether generators follow the intended response policy.

27 Aug 2026
Agent Harnesses

Separating state tracking from actions improves multi-turn tool reliability

Guo et al. introduce a structured tool-use policy that separates reconstructing task state, deciding whether to act, specifying an admissible action, and producing the final output. Across multi-turn, multi-tool, and incomplete-information evaluations, the authors report more reliable task completion than direct function calling and ReAct, especially for smaller models and tasks dependent on earlier context.

27 Aug 2026
Safety & Evals

Physiological grounding makes clinical language-model recommendations safer in controlled tests

Abdullah, Cambria and Živković coupled a clinical language model to a graph-based physiological world model that ranks candidate answers using homeostatic constraints, biomedical paths and drug-interaction penalties. On a 2,500-scenario safety benchmark, their training method raised the main safety score from 69.5% to 90.8% and reduced physician-evaluated harm from 14.1% to 5.1% on a blinded subset.

27 Aug 2026