Thompson Sampling For Combinatorial Bandits: Polynomial Regret and Mismatched Sampling Paradox

December 9, 2024·
Raymond Zhang
Raymond Zhang
,
Richard Combes
Abstract
We consider Thompson Sampling (TS) for linear combinatorial semi-bandits and subgaussian rewards. We propose the first known TS whose finite-time regret does not scale exponentially with the dimension of the problem. We further show the “mismatched sampling paradox”: A learner who knows the rewards distributions and samples from the correct posterior distribution can perform exponentially worse than a learner who does not know the rewards and simply samples from a well-chosen Gaussian posterior.
Type
Publication
In Neural Information Processing Systems 2024
publications
Raymond Zhang
Authors
PhD Student at CentraleSupélec

I am currently a PostDoc at Inria Lille in the Scool team. I am under the supervision Emilie Kaufmann and Remy Degenne. My research interests are around sequential learning, mostly for bandits (Active identification and cumulative regret) and communication / information theory.

Between 2022 and 2025, I was a PhD Student at the L2S lab at CentraleSupélec under the supervision of Richard Combes and Sheng Yang

Authors
Maitre de Conférence