Hypergradient-based Bilevel Reinforcement Learning with Improved Sample Complexity
- URL: http://arxiv.org/abs/2607.28849v1
- Date: Thu, 30 Jul 2026 21:21:52 GMT
- Title: Hypergradient-based Bilevel Reinforcement Learning with Improved Sample Complexity
- Abstract summary: We propose a hypergradient-based bilevel RL algorithm using the optimality of the Boltzmann policy for the entropy regularized discounted RL objective function.<n>Our proposed algorithm is Hessian-free and obtains an iteration complexity of $O(-1)$ and state-of-the-art sample complexity of $tildeO(-2)$ under mild regularity conditions.
- Score: 44.384258745074646
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Bilevel reinforcement learning (RL) is an important framework within the literature of RL that can be used to formalize various categories of problems, such as meta-learning, hierarchical task decomposition, and reinforcement learning from human feedback (RL-HF). Most of the bilevel RL algorithms are either not scalable because of using hypergradient with Hessian, or they suffer from high sample complexity because of using penalty-based approximation methods. In this work, we propose a hypergradient-based bilevel RL algorithm using the optimality of the Boltzmann policy for the entropy regularized discounted RL objective function. Our proposed algorithm is Hessian-free and obtains an iteration complexity of $O(ε^{-1})$ and state-of-the-art sample complexity of $\tilde{O}(ε^{-2})$ under mild regularity conditions. Further, in our convergence analysis, we are able to remove the assumption of the Polyak-Lojasiewicz (PL) condition on the outer-level objective function present in the prior state-of-the-art sample complexity work.
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