Kernelized Reinforcement Learning with Order Optimal Regret Bounds

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Vakili, Sattar, Olkhovskaya, Julia
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911796727644160
author Vakili, Sattar
Olkhovskaya, Julia
author_facet Vakili, Sattar
Olkhovskaya, Julia
contents Reinforcement learning (RL) has shown empirical success in various real world settings with complex models and large state-action spaces. The existing analytical results, however, typically focus on settings with a small number of state-actions or simple models such as linearly modeled state-action value functions. To derive RL policies that efficiently handle large state-action spaces with more general value functions, some recent works have considered nonlinear function approximation using kernel ridge regression. We propose $π$-KRVI, an optimistic modification of least-squares value iteration, when the state-action value function is represented by a reproducing kernel Hilbert space (RKHS). We prove the first order-optimal regret guarantees under a general setting. Our results show a significant polynomial in the number of episodes improvement over the state of the art. In particular, with highly non-smooth kernels (such as Neural Tangent kernel or some Matérn kernels) the existing results lead to trivial (superlinear in the number of episodes) regret bounds. We show a sublinear regret bound that is order optimal in the case of Matérn kernels where a lower bound on regret is known.
format Preprint
id arxiv_https___arxiv_org_abs_2306_07745
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Kernelized Reinforcement Learning with Order Optimal Regret Bounds
Vakili, Sattar
Olkhovskaya, Julia
Machine Learning
Artificial Intelligence
Reinforcement learning (RL) has shown empirical success in various real world settings with complex models and large state-action spaces. The existing analytical results, however, typically focus on settings with a small number of state-actions or simple models such as linearly modeled state-action value functions. To derive RL policies that efficiently handle large state-action spaces with more general value functions, some recent works have considered nonlinear function approximation using kernel ridge regression. We propose $π$-KRVI, an optimistic modification of least-squares value iteration, when the state-action value function is represented by a reproducing kernel Hilbert space (RKHS). We prove the first order-optimal regret guarantees under a general setting. Our results show a significant polynomial in the number of episodes improvement over the state of the art. In particular, with highly non-smooth kernels (such as Neural Tangent kernel or some Matérn kernels) the existing results lead to trivial (superlinear in the number of episodes) regret bounds. We show a sublinear regret bound that is order optimal in the case of Matérn kernels where a lower bound on regret is known.
title Kernelized Reinforcement Learning with Order Optimal Regret Bounds
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2306.07745