activity
20222025
most citedMutation-Driven Follow the Regularized Leader for Last-Iterate Convergence in Zero-Sum Games

5 citations · 6 across the 8 of their papers we have counts for

collaborators

9 papers

cs.LG2025

MO-GRPO: Mitigating Reward Hacking of Group Relative Policy Optimization on Multi-Objective Problems

Yuki Ichihara, Yuu Jinnai, Tetsuro Morimura +3

Group Relative Policy Optimization (GRPO) has been shown to be an effective algorithm when an accurate reward model is available. However, such a highly reliable reward model is no…

math.OC2025

Asymmetric Perturbation in Solving Bilinear Saddle-Point Optimization

Kenshi Abe, Mitsuki Sakamoto, Kaito Ariu +1

This paper proposes asymmetric perturbation, where only one player's payoff function is perturbed, for solving bilinear saddle-point optimization problems, commonly arising in mini…

cs.CL2025

Evaluation of Best-of-N Sampling Strategies for Language Model Alignment

Yuki Ichihara, Yuu Jinnai, Tetsuro Morimura +4

Best-of-N (BoN) sampling with a reward model has been shown to be an effective strategy for aligning Large Language Models (LLMs) with human preferences at the time of decoding. Bo…

cs.GT2025

On the Power of Perturbation under Sampling in Solving Extensive-Form Games

Wataru Masaka, Mitsuki Sakamoto, Kenshi Abe +3

We investigate how perturbation does and does not improve the Follow-the-Regularized-Leader (FTRL) algorithm in solving imperfect-information extensive-form games under sampling, w…

cs.GT2024

Boosting Perturbed Gradient Ascent for Last-Iterate Convergence in Games

Kenshi Abe, Mitsuki Sakamoto, Kaito Ariu +1

This paper presents a payoff perturbation technique, introducing a strong convexity to players' payoff functions in games. This technique is specifically designed for first-order m…

cs.LG2024★ 1 cited

Filtered Direct Preference Optimization

Tetsuro Morimura, Mitsuki Sakamoto, Yuu Jinnai +2

Reinforcement learning from human feedback (RLHF) plays a crucial role in aligning language models with human preferences. While the significance of dataset quality is generally re…

cs.GT2023

Adaptively Perturbed Mirror Descent for Learning in Games

Kenshi Abe, Kaito Ariu, Mitsuki Sakamoto +1

This paper proposes a payoff perturbation technique for the Mirror Descent (MD) algorithm in games where the gradient of the payoff functions is monotone in the strategy profile sp…

cs.GT2022

Last-Iterate Convergence with Full and Noisy Feedback in Two-Player Zero-Sum Games

Kenshi Abe, Kaito Ariu, Mitsuki Sakamoto +2

This paper proposes Mutation-Driven Multiplicative Weights Update (M2WU) for learning an equilibrium in two-player zero-sum normal-form games and proves that it exhibits the last-i…

cs.GT2022★ 5 cited

Mutation-Driven Follow the Regularized Leader for Last-Iterate Convergence in Zero-Sum Games

Kenshi Abe, Mitsuki Sakamoto, Atsushi Iwasaki

In this study, we consider a variant of the Follow the Regularized Leader (FTRL) dynamics in two-player zero-sum games. FTRL is guaranteed to converge to a Nash equilibrium when ti…