DFPO: Scaling Value Modeling via Distributional Flow towards Robust and Generalizable LLM Post-Training

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhu, Dingwei, Xi, Zhiheng, Dou, Shihan, Li, Jiahan, Huang, Chenhao, Ye, Junjie, Li, Sixian, Chai, Mingxu, Wang, Yuhui, Yang, Yajie, Zhang, Ming, Zhang, Jiazheng, Liu, Shichun, Huang, Caishuang, Zhang, Yunke, Wang, Yuran, Gui, Tao, Qiu, Xipeng, Zhang, Qi, Huang, Xuanjing
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915982838071296
author Zhu, Dingwei
Xi, Zhiheng
Dou, Shihan
Li, Jiahan
Huang, Chenhao
Ye, Junjie
Li, Sixian
Chai, Mingxu
Wang, Yuhui
Yang, Yajie
Zhang, Ming
Zhang, Jiazheng
Liu, Shichun
Huang, Caishuang
Zhang, Yunke
Wang, Yuran
Gui, Tao
Qiu, Xipeng
Zhang, Qi
Huang, Xuanjing
author_facet Zhu, Dingwei
Xi, Zhiheng
Dou, Shihan
Li, Jiahan
Huang, Chenhao
Ye, Junjie
Li, Sixian
Chai, Mingxu
Wang, Yuhui
Yang, Yajie
Zhang, Ming
Zhang, Jiazheng
Liu, Shichun
Huang, Caishuang
Zhang, Yunke
Wang, Yuran
Gui, Tao
Qiu, Xipeng
Zhang, Qi
Huang, Xuanjing
contents Training reinforcement learning (RL) systems in real-world environments remains challenging due to noisy supervision and poor out-of-domain (OOD) generalization, especially in LLM post-training. Recent distributional RL methods improve robustness by modeling values with multiple quantile points, but they still learn each quantile independently as a scalar. This results in rough-grained value representations that lack fine-grained conditioning on state information, struggling under complex and OOD conditions. We propose DFPO (Distributional Value Flow Policy Optimization with Conditional Risk and Consistency Control), a robust distributional RL framework that models values as continuous flows across time steps. By scaling value modeling through learning of a value flow field instead of isolated quantile predictions, DFPO captures richer state information for more accurate advantage estimation. To stabilize training under noisy feedback, DFPO further integrates conditional risk control and consistency constraints along value flow trajectories. Experiments on dialogue, math reasoning, and scientific tasks show that DFPO outperforms PPO, FlowRL, and other robust baselines under noisy supervision, achieving improved training stability and generalization.
format Preprint
id arxiv_https___arxiv_org_abs_2602_05890
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle DFPO: Scaling Value Modeling via Distributional Flow towards Robust and Generalizable LLM Post-Training
Zhu, Dingwei
Xi, Zhiheng
Dou, Shihan
Li, Jiahan
Huang, Chenhao
Ye, Junjie
Li, Sixian
Chai, Mingxu
Wang, Yuhui
Yang, Yajie
Zhang, Ming
Zhang, Jiazheng
Liu, Shichun
Huang, Caishuang
Zhang, Yunke
Wang, Yuran
Gui, Tao
Qiu, Xipeng
Zhang, Qi
Huang, Xuanjing
Machine Learning
Computation and Language
Training reinforcement learning (RL) systems in real-world environments remains challenging due to noisy supervision and poor out-of-domain (OOD) generalization, especially in LLM post-training. Recent distributional RL methods improve robustness by modeling values with multiple quantile points, but they still learn each quantile independently as a scalar. This results in rough-grained value representations that lack fine-grained conditioning on state information, struggling under complex and OOD conditions. We propose DFPO (Distributional Value Flow Policy Optimization with Conditional Risk and Consistency Control), a robust distributional RL framework that models values as continuous flows across time steps. By scaling value modeling through learning of a value flow field instead of isolated quantile predictions, DFPO captures richer state information for more accurate advantage estimation. To stabilize training under noisy feedback, DFPO further integrates conditional risk control and consistency constraints along value flow trajectories. Experiments on dialogue, math reasoning, and scientific tasks show that DFPO outperforms PPO, FlowRL, and other robust baselines under noisy supervision, achieving improved training stability and generalization.
title DFPO: Scaling Value Modeling via Distributional Flow towards Robust and Generalizable LLM Post-Training
topic Machine Learning
Computation and Language
url https://arxiv.org/abs/2602.05890