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Sam Lobel

4 accepted papers

2025

Skill-Driven Neurosymbolic State Abstractions

NeurIPS 2025poster

We consider how to construct state abstractions compatible with a given set of abstract actions, to obtain a well-formed abstract Markov decision process (MDP). We show that the Bellman equation suggests that abstract states should represent distributions over states in the ground MDP; we characteri…

Cited by 0SourceScholar
2024

Mitigating Partial Observability in Sequential Decision Processes via the Lambda Discrepancy

NeurIPS 2024poster

Reinforcement learning algorithms typically rely on the assumption that the environment dynamics and value function can be expressed in terms of a Markovian state representation. However, when state information is only partially observable, how can an agent learn such a state representation, and how…

2023

Flipping Coins to Estimate Pseudocounts for Exploration in Reinforcement Learning

ICML 2023oral

We propose a new method for count-based exploration in high-dimensional state spaces. Unlike previous work which relies on density models, we show that counts can be derived by averaging samples from the Rademacher distribution (or coin flips). This insight is used to set up a simple supervised lear…

2022

Optimistic Initialization for Exploration in Continuous Control

AAAI 2022technical

Optimistic initialization underpins many theoretically sound exploration schemes in tabular domains; however, in the deep function approximation setting, optimism can quickly disappear if initialized naively. We propose a framework for more effectively incorporating optimistic initialization into re…

Cited by 14SourcePDFScholar