Reinforcement learning

Policy optimisation, reward modelling and RLHF — how models are trained by feedback rather than by labels.

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arXiv AI
1d ago

VisualEvolve: A Skill Self-Evolution Framework for Visual Reasoning

arXiv:2610.28386v1 Announce Type: cross Abstract: Visual tool use enables vision-language models (VLMs) to acquire task-relevant evidence, but its effectiveness can be limited by predefined visual op...

By Jiawei Wang, Yucun Li, Xueqi Li, Shenghao Wang, Xinquan Gong, Dan Zhang, Zheqi Lv, Yuquan Le, Shaozu Yuan, An Zhang, Da Cao, Tat-Seng Chua
arXiv AI
1d ago

A Survey of Generative Categories and Techniques in Multimodal Generative Models

The paper surveys multimodal generative models (MGMs), outlining six main text‑conditioned modalities and four key techniques—self‑supervised learning, mixture of experts, reinforcement learning from human feedback, and chain‑of‑thought prompting—used across them. It evaluates models on faithfulness, compositionality, and robustness, and reports four empirical findings about preference gains, reward optimisation, intermediate planning, and expert granularity. The study also discusses trustworthiness risks such as bias, privacy leakage, and media misuse, and reviews mitigation evidence.

By Longzhen Han, Awes Mubarak, Almas Baimagambetov, Nikolaos Polatidis, Thar Baker
arXiv Machine Learning
3d ago

Multi-Agent Reinforcement Learning-Based UAV Pathfinding for Obstacle Avoidance in Stochastic Environment

The paper proposes a centralized training with decentralized execution framework for multi‑agent UAV pathfinding in stochastic environments, leveraging multi‑agent reinforcement learning enhanced by model predictive control concepts. Agents communicate only with a centralized planner and use a distance‑weighted mean‑field observation to plan feasible paths, while multi‑step value convergence improves training efficiency. Experiments, including ablation and real‑robot studies, demonstrate the method’s effectiveness and generalization.

By Qizhen Wu, Kexin Liu, Lei Chen, Jinhu L\"u
arXiv AI
3d ago

Compression Precedes, Content Decides: Emergent Misalignment in Reward Models

The paper investigates emergent misalignment in reward models, showing that fine‑tuning reward models to prefer harmful content in a single domain (medical or financial) causes the preference to generalize to seven other domains. The authors fine‑tune two state‑of‑the‑art reward models—Skywork‑Reward‑V2‑Llama‑3.1‑8B and Skywork‑Reward‑V2‑Qwen3‑8B—and find that the models still perform well on the standard RewardBench 2 evaluation while exhibiting a preference for harm. Mechanistically, the study identifies two key changes in the reward models’ representations: a geometric compression that reduces the angle between sound and harmful responses, and a content‑specific rotation that aligns harmful representations more closely with the scalar head, thereby increasing their reward score.

By Dhruv Puri, Nikhil Prakash
arXiv AI
3d ago

RECREG: Recovery-based Shielding for Regular Safety Properties in Reinforcement Learning

The paper introduces RecReg, a safe reinforcement learning framework that enforces non‑Markovian regular safety properties through recovery‑based shielding. It provides theoretical foundations and rigorous safety and convergence guarantees in the tabular setting, and demonstrates empirical effectiveness using the MASA‑Safe‑RL library. The authors also outline an extension of RecReg to deep RL with state‑of‑the‑art model‑based methods.

By Alexander W. Goodall, Francesco Belardinelli
arXiv Computer Vision
3d ago

SCALE: Improving Guidance-Free Visual Generation via Self-Contrastive Alignment for Likelihood Estimation

The paper introduces Self-Contrastive Guidance (SCG), a method that contrasts a model’s predictions on real versus self-generated samples to directly guide generation toward the true data manifold. SCG is incorporated into the likelihood objective through reparameterization, resulting in the Self-Contrastive Alignment for Likelihood Estimation (SCALE) framework, which produces SCG-enhanced predictions in a single forward pass. Experiments on class-conditional and text-to-image generation with diffusion and autoregressive models show that SCALE consistently outperforms existing guidance-free baselines and further benefits from combining with Direct Preference Optimization (DPO).

By Jiwan Hur, Dong-Jae Lee, Dongyeun Lee, Gyojin Han, Junmo Kim
arXiv AI
3d ago

Tree-Aware Posterior Distillation for Long-Horizon Agentic Reinforcement Learning

Tree-Aware Posterior Distillation for Long-Horizon Agentic Reinforcement Learning proposes TreeOPSD, a critic‑free framework that treats each interaction turn as a tree node, branches alternative continuations, and recursively backs up terminal rewards to generate implicit turn‑level credit. The method maps this credit to a bounded teacher distribution based on the likelihood ratio to a frozen behavior policy, and minimizes the divergence between teacher and student to recover policy‑gradient directions while limiting updates across mini‑batches. Empirical results show TreeOPSD enhances agentic performance on long‑horizon benchmarks, notably improving Qwen3‑30B‑A3B‑Thinking‑2507’s accuracy by 4.97 points over GRPO in the Deep Research setting.

By Heming Zou, Qi Wang, Yixiu Mao, Yun Qu, Yuyi Guo, Zeyuan Liu, Chenglin Li, Weijie Liu, Saiyong Yang, Xiangyang Ji