Bayesian Exploration Networks

Fuente: arXiv
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Main Authors: Fellows, Mattie, Kaplowitz, Brandon, de Witt, Christian Schroeder, Whiteson, Shimon
Format: Preprint
Published: 2023
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author Fellows, Mattie
Kaplowitz, Brandon
de Witt, Christian Schroeder
Whiteson, Shimon
author_facet Fellows, Mattie
Kaplowitz, Brandon
de Witt, Christian Schroeder
Whiteson, Shimon
contents Bayesian reinforcement learning (RL) offers a principled and elegant approach for sequential decision making under uncertainty. Most notably, Bayesian agents do not face an exploration/exploitation dilemma, a major pathology of frequentist methods. However theoretical understanding of model-free approaches is lacking. In this paper, we introduce a novel Bayesian model-free formulation and the first analysis showing that model-free approaches can yield Bayes-optimal policies. We show all existing model-free approaches make approximations that yield policies that can be arbitrarily Bayes-suboptimal. As a first step towards model-free Bayes optimality, we introduce the Bayesian exploration network (BEN) which uses normalising flows to model both the aleatoric uncertainty (via density estimation) and epistemic uncertainty (via variational inference) in the Bellman operator. In the limit of complete optimisation, BEN learns true Bayes-optimal policies, but like in variational expectation-maximisation, partial optimisation renders our approach tractable. Empirical results demonstrate that BEN can learn true Bayes-optimal policies in tasks where existing model-free approaches fail.
format Preprint
id arxiv_https___arxiv_org_abs_2308_13049
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Bayesian Exploration Networks
Fellows, Mattie
Kaplowitz, Brandon
de Witt, Christian Schroeder
Whiteson, Shimon
Machine Learning
Bayesian reinforcement learning (RL) offers a principled and elegant approach for sequential decision making under uncertainty. Most notably, Bayesian agents do not face an exploration/exploitation dilemma, a major pathology of frequentist methods. However theoretical understanding of model-free approaches is lacking. In this paper, we introduce a novel Bayesian model-free formulation and the first analysis showing that model-free approaches can yield Bayes-optimal policies. We show all existing model-free approaches make approximations that yield policies that can be arbitrarily Bayes-suboptimal. As a first step towards model-free Bayes optimality, we introduce the Bayesian exploration network (BEN) which uses normalising flows to model both the aleatoric uncertainty (via density estimation) and epistemic uncertainty (via variational inference) in the Bellman operator. In the limit of complete optimisation, BEN learns true Bayes-optimal policies, but like in variational expectation-maximisation, partial optimisation renders our approach tractable. Empirical results demonstrate that BEN can learn true Bayes-optimal policies in tasks where existing model-free approaches fail.
title Bayesian Exploration Networks
topic Machine Learning
url https://arxiv.org/abs/2308.13049