arXiv Machine Learning By Mohammad Mahdi Salmani-Zarchi, Zahra Rahimi, Heshaam Faili, Mohammad Javad Dousti

MDP-GRPO: Stabilized Group Relative Policy Optimization for Multi-Constraint Instruction Following

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arXiv:2606. 06058v1 Announce Type: new Abstract: Reinforcement learning with verifiable rewards is ideal for multi-constraint instruction following, yet standard group-relative policy optimization (GRPO) becomes unstable under discrete, low-dispersion rewards, where within-group reward distributions are frequently homogeneous.

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Why GRPO Needs Normalization: A Local-Curvature Perspective on Adaptive Gradients

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