activity
20242026
collaborators

6 papers

cs.LG2026

An Improved Model-Free Decision-Estimation Coefficient with Applications in Adversarial MDPs

Haolin Liu, Chen-Yu Wei, Julian Zimmert

We study decision making with structured observation (DMSO). Previous work (Foster et al., 2021b, 2023a) has characterized the complexity of DMSO via the decision-estimation coeffi…

cs.LG2025

Decision Making in Hybrid Environments: A Model Aggregation Approach

Haolin Liu, Chen-Yu Wei, Julian Zimmert

Recent work by Foster et al. (2021, 2022, 2023b) and Xu and Zeevi (2023) developed the framework of decision estimation coefficient (DEC) that characterizes the complexity of gener…

cs.LG2024

A Model Selection Approach for Corruption Robust Reinforcement Learning

Chen-Yu Wei, Christoph Dann, Julian Zimmert

We develop a model selection approach to tackle reinforcement learning with adversarial corruption in both transition and reward. For finite-horizon tabular MDPs, without prior kno…

cs.LG2024

Beating Adversarial Low-Rank MDPs with Unknown Transition and Bandit Feedback

Haolin Liu, Zakaria Mhammedi, Chen-Yu Wei +1

We consider regret minimization in low-rank MDPs with fixed transition and adversarial losses. Previous work has investigated this problem under either full-information loss feedba…

cs.LG2024

A Best-of-both-worlds Algorithm for Bandits with Delayed Feedback with Robustness to Excessive Delays

Saeed Masoudian, Julian Zimmert, Yevgeny Seldin

We propose a new best-of-both-worlds algorithm for bandits with variably delayed feedback. In contrast to prior work, which required prior knowledge of the maximal delay $d_{\mathr…

cs.LG2024

Incentive-compatible Bandits: Importance Weighting No More

Julian Zimmert, Teodor V. Marinov

We study the problem of incentive-compatible online learning with bandit feedback. In this class of problems, the experts are self-interested agents who might misrepresent their pr…