Asymmetric Advantage Modulation Calibrates Entropy Dynamics in RLVR

Fuente: arXiv
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Hauptverfasser: Gu, Hengrui, Han, Xiaotian, Bian, Yujing, Wang, Feiyi, Zhou, Kaixiong
Format: Preprint
Veröffentlicht: 2026
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author Gu, Hengrui
Han, Xiaotian
Bian, Yujing
Wang, Feiyi
Zhou, Kaixiong
author_facet Gu, Hengrui
Han, Xiaotian
Bian, Yujing
Wang, Feiyi
Zhou, Kaixiong
contents Reinforcement learning with verifiable rewards (RLVR) has substantially improved the reasoning ability of large language models (LLMs), but it often suffers from \textit{restricted exploration}, where the policy rapidly concentrates on a narrow set of solutions. A common remedy is entropy regularization, which attempts to preserve exploration by increasing policy entropy. However, for LLM-RL, this intervention is highly sensitive to its coefficient, can introduce semantically weak uncertainty, and often yields limited accuracy gains. This motivates a more precise question: which entropy helps reasoning, and which entropy should be reduced? To study this, we parameterize the advantage estimator in Group Relative Policy Optimization (GRPO) into positive and negative outcome-conditioned channels and analyze their entropy dynamics. Our results show that positive-channel modulation raises \textit{productive entropy} associated with successful reasoning trajectories, while negative-channel modulation removes \textit{noisy entropy} associated with failed rollouts and reduces interference with correct paths. Guided by this channel-wise view, we propose \textbf{AsymGRPO}, which decouples the modulation strengths of positive and negative advantages. This enables flexible control over how the model updates across prompt difficulty levels, allowing stronger reinforcement of rare successes on harder prompts or stronger suppression of residual failures on easier prompts without forcing the two channels to share the same modulation strength. Experiments on five mathematical reasoning benchmarks show that AsymGRPO outperforms strong RLVR baselines, with consistent gains across model backbones.
format Preprint
id arxiv_https___arxiv_org_abs_2604_04894
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Asymmetric Advantage Modulation Calibrates Entropy Dynamics in RLVR
Gu, Hengrui
Han, Xiaotian
Bian, Yujing
Wang, Feiyi
Zhou, Kaixiong
Computation and Language
Artificial Intelligence
Machine Learning
Reinforcement learning with verifiable rewards (RLVR) has substantially improved the reasoning ability of large language models (LLMs), but it often suffers from \textit{restricted exploration}, where the policy rapidly concentrates on a narrow set of solutions. A common remedy is entropy regularization, which attempts to preserve exploration by increasing policy entropy. However, for LLM-RL, this intervention is highly sensitive to its coefficient, can introduce semantically weak uncertainty, and often yields limited accuracy gains. This motivates a more precise question: which entropy helps reasoning, and which entropy should be reduced? To study this, we parameterize the advantage estimator in Group Relative Policy Optimization (GRPO) into positive and negative outcome-conditioned channels and analyze their entropy dynamics. Our results show that positive-channel modulation raises \textit{productive entropy} associated with successful reasoning trajectories, while negative-channel modulation removes \textit{noisy entropy} associated with failed rollouts and reduces interference with correct paths. Guided by this channel-wise view, we propose \textbf{AsymGRPO}, which decouples the modulation strengths of positive and negative advantages. This enables flexible control over how the model updates across prompt difficulty levels, allowing stronger reinforcement of rare successes on harder prompts or stronger suppression of residual failures on easier prompts without forcing the two channels to share the same modulation strength. Experiments on five mathematical reasoning benchmarks show that AsymGRPO outperforms strong RLVR baselines, with consistent gains across model backbones.
title Asymmetric Advantage Modulation Calibrates Entropy Dynamics in RLVR
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2604.04894