arXiv Machine Learning

Minimax Optimal Strategy for Delayed Observations in Online Reinforcement Learning

arXiv:2603. 03480v2 Announce Type: replace Abstract: We study reinforcement learning with delayed state observation, where the agent observes the current state after some random number of time steps.

arXiv Machine Learning
Sep 11

Near-Optimal Reinforcement Learning with Multi-Step Transition Lookahead

The paper investigates reinforcement learning with multi‑step transition look‑ahead, where an agent can foresee the states resulting from any sequence of λ actions before choosing its next move. It proves that exact planning remains NP‑hard for every fixed rational discount factor γ in (0,1), and introduces a randomized polynomial‑time approximation scheme that works for any fixed look‑ahead depth. Extending this to unknown transitions and stochastic rewards, the authors develop an algorithm with cumulative regret matching classical tabular discounted RL up to logarithmic factors, showing that efficient near‑optimal planning and learning are achievable despite the NP‑hardness of exact planning.

By Corentin Pla, Hugo Richard, Marc Abeille, Vianney Perchet
arXiv Machine Learning
Jun 3

Data- and Variance-dependent Regret Bounds for Online Tabular MDPs

arXiv:2602. 01903v2 Announce Type: replace Abstract: This work studies online episodic tabular Markov decision processes (MDPs) with known transitions and develops best-of-both-worlds algorithms that achieve refined data-dependent regret bounds in the adversarial regime and variance-dependent regret bounds in the stochastic regime.

By Mingyi Li, Taira Tsuchiya, Kenji Yamanishi