Gap-Dependent Bounds for Nearly Minimax Optimal Reinforcement Learning with Linear Function Approximation
- URL: http://arxiv.org/abs/2602.20297v1
- Date: Mon, 23 Feb 2026 19:25:46 GMT
- Title: Gap-Dependent Bounds for Nearly Minimax Optimal Reinforcement Learning with Linear Function Approximation
- Authors: Haochen Zhang, Zhong Zheng, Lingzhou Xue,
- Abstract summary: We provide the first gap-dependent regret bound for the nearly minimax-optimal algorithm LSVI-UCB++.<n>Our analysis yields improved dependencies on both $d$ and $H$ compared to previous gap-dependent results.
- Score: 13.370933509246568
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We study gap-dependent performance guarantees for nearly minimax-optimal algorithms in reinforcement learning with linear function approximation. While prior works have established gap-dependent regret bounds in this setting, existing analyses do not apply to algorithms that achieve the nearly minimax-optimal worst-case regret bound $\tilde{O}(d\sqrt{H^3K})$, where $d$ is the feature dimension, $H$ is the horizon length, and $K$ is the number of episodes. We bridge this gap by providing the first gap-dependent regret bound for the nearly minimax-optimal algorithm LSVI-UCB++ (He et al., 2023). Our analysis yields improved dependencies on both $d$ and $H$ compared to previous gap-dependent results. Moreover, leveraging the low policy-switching property of LSVI-UCB++, we introduce a concurrent variant that enables efficient parallel exploration across multiple agents and establish the first gap-dependent sample complexity upper bound for online multi-agent RL with linear function approximation, achieving linear speedup with respect to the number of agents.
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