arXiv Machine Learning

Scalar-Stepsize Nonuniform Monte Carlo Optimistic Policy Iteration: A Certified Counterexample

arXiv:2606. 15978v1 Announce Type: new Abstract: Tsitsiklis proved convergence of Monte Carlo optimistic policy iteration under a uniform update structure and identified nonuniform update frequencies as a delicate obstruction.

arXiv Machine Learning
Aug 19

A Finite-Iteration Theory for Asynchronous Categorical Distributional Temporal-Difference Learning

The paper investigates the finite‑iteration behavior of exact asynchronous recursions used in categorical distributional temporal‑difference (TD) learning. It analyzes both scalar categorical TD in the Cramér geometry and multivariate signed‑categorical TD in the maximum mean discrepancy geometry, showing that these methods can be viewed as single‑state stochastic‑approximation recursions that contract in a block‑supremum norm. The authors develop a restricted‑domain theory, derive discounted bounds under i.i.d. and Markovian sampling, and extend the analysis to undiscounted fixed‑horizon policy evaluation with horizon‑stacked categorical methods under episodic sampling, thereby providing a unified non‑asymptotic analysis across various settings.

By Ege C. Kaya, Abolfazl Hashemi
arXiv Machine Learning
Jul 1

End-to-End Efficient RL for Linear Bellman Complete MDPs with Deterministic Transitions

arXiv:2603. 23461v2 Announce Type: replace Abstract: We study reinforcement learning (RL) with linear function approximation in Markov Decision Processes (MDPs) satisfying \emph{linear Bellman completeness} -- a fundamental setting where the Bellman backup of any linear value function remains linear.

By Zakaria Mhammedi, Alexander Rakhlin, Nneka Okolo