arXiv AI
Oct 31

SHPRR: An Algorithm for Pure Exploration under Constrained Regret

The paper introduces SHPRR, an algorithm that adapts Sequential Halving for pure exploration problems where regret relative to a baseline is a key cost metric. It shows that regret cost decreases as the algorithm progresses, allowing a front‑loaded allocation of the regret budget to improve best‑arm identification. Experiments on synthetic and real data demonstrate that SHPRR outperforms uniform regret allocation and existing baselines.

By Georgina Nouli, Flore Sentenac, Maximilian Schiffer
arXiv AI
Oct 15

Rethinking Langevin Thompson Sampling from A Stochastic Approximation Perspective

The paper introduces TS-SA, a variant of Langevin-based Thompson Sampling that integrates stochastic approximation into the bandit framework. TS-SA performs a single Langevin step per new reward and updates a persistent Markov chain for each arm, avoiding repeated sampling of past data. This approach yields a near‑optimal worst‑case regret bound of ≥O(√{KT}) under log‑concavity and smoothness, and empirical results show strong performance against standard baselines.

By Weixin Wang, Haoyang Zheng, Guang Lin, Wei Deng, Pan Xu
arXiv AI
Jun 2

MINTS: Minimalist Thompson Sampling

arXiv:2606. 01655v1 Announce Type: cross Abstract: The Bayesian paradigm offers principled tools for sequential decision-making under uncertainty, but its reliance on a probabilistic model for all parameters can hinder the incorporation of complex structural constraints.

By Kaizheng Wang
arXiv Machine Learning
Jun 26

Target-Aware Bandit Allocation for Scalable Surrogate Optimization in Chemical Space

arXiv:2606. 26657v1 Announce Type: new Abstract: Identifying high-utility candidates from massive discrete spaces under expensive evaluations is a recurring challenge across the sciences, with structure-based drug discovery as a prominent example.

By Mohammad Haddadnia, Yuvan Chali, Abhilash Jayaraj, Constance Kraay, Joana Reis, Felix Strieth-Kalthoff, Haribabu Arthanari
arXiv Machine Learning
Jun 30

Randomized Exploration for Linear Bandits via Absolute Perturbations

arXiv:2606. 28616v1 Announce Type: new Abstract: In stochastic linear bandits, the canonical Upper Confidence Bound (UCB) algorithm admits a simple frequentist regret analysis but can be computationally demanding, while Thompson Sampling (TS) is computationally attractive yet typically harder to analyze due to its non-optimistic nature.

By Toshinori Kitamura, Shuai Liu, Csaba Szepesv\'ari