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We study linear bandits when the underlying reward function is not linear. Existing work relies on a uniform misspecification parameter $\epsilon$ that measures the sup-norm error of the best linear approximation. This results in an…

Machine Learning · Computer Science 2023-07-21 Chong Liu , Ming Yin , Yu-Xiang Wang

We study the problem of corralling stochastic bandit algorithms, that is combining multiple bandit algorithms designed for a stochastic environment, with the goal of devising a corralling algorithm that performs almost as well as the best…

Machine Learning · Computer Science 2021-03-02 Raman Arora , Teodor V. Marinov , Mehryar Mohri

Modern systems, such as digital platforms and service systems, increasingly rely on contextual bandits for online decision-making; however, their deployment can inadvertently create unfair exposure among arms, undermining long-term platform…

Machine Learning · Statistics 2026-02-05 Qingwen Zhang , Wenjia Wang

Motivated by real-world applications that necessitate responsible experimentation, we introduce the problem of best arm identification (BAI) with minimal regret. This innovative variant of the multi-armed bandit problem elegantly…

Machine Learning · Computer Science 2024-09-30 Junwen Yang , Vincent Y. F. Tan , Tianyuan Jin

We consider the problem of online learning in misspecified linear stochastic multi-armed bandit problems. Regret guarantees for state-of-the-art linear bandit algorithms such as Optimism in the Face of Uncertainty Linear bandit (OFUL) hold…

Machine Learning · Computer Science 2017-04-25 Avishek Ghosh , Sayak Ray Chowdhury , Aditya Gopalan

We study the stochastic multi-armed bandit problem with the graph-based feedback structure introduced by Mannor and Shamir. We analyze the performance of the two most prominent stochastic bandit algorithms, Thompson Sampling and Upper…

Machine Learning · Computer Science 2020-02-17 Thodoris Lykouris , Eva Tardos , Drishti Wali

Multi-armed bandits (MAB) model sequential decision making problems, in which a learner sequentially chooses arms with unknown reward distributions in order to maximize its cumulative reward. Most of the prior work on MAB assumes that the…

Machine Learning · Computer Science 2018-03-22 Onur Atan , Cem Tekin , Mihaela van der Schaar

We propose a simple model selection approach for algorithms in stochastic bandit and reinforcement learning problems. As opposed to prior work that (implicitly) assumes knowledge of the optimal regret, we only require that each base…

Machine Learning · Computer Science 2020-12-25 Aldo Pacchiano , Christoph Dann , Claudio Gentile , Peter Bartlett

Recent studies have shown that reinforcement learning with KL-regularized objectives can enjoy faster rates of convergence or logarithmic regret, in contrast to the classical $\sqrt{T}$-type regret in the unregularized setting. However, the…

Machine Learning · Computer Science 2026-03-03 Kaixuan Ji , Qingyue Zhao , Heyang Zhao , Qiwei Di , Quanquan Gu

This paper considers the use of a simple posterior sampling algorithm to balance between exploration and exploitation when learning to optimize actions such as in multi-armed bandit problems. The algorithm, also known as Thompson Sampling,…

Machine Learning · Computer Science 2014-02-04 Daniel Russo , Benjamin Van Roy

We consider the classic online learning and stochastic multi-armed bandit (MAB) problems, when at each step, the online policy can probe and find out which of a small number ($k$) of choices has better reward (or loss) before making its…

Data Structures and Algorithms · Computer Science 2022-11-08 Aditya Bhaskara , Sreenivas Gollapudi , Sungjin Im , Kostas Kollias , Kamesh Munagala

We investigate the problem of maximizing social welfare while ensuring fairness in a multi-agent multi-armed bandit (MA-MAB) setting. In this problem, a centralized decision-maker takes actions over time, generating random rewards for…

Machine Learning · Computer Science 2025-06-23 Piyushi Manupriya , Himanshu , SakethaNath Jagarlapudi , Ganesh Ghalme

This work studies linear bandits under a new notion of gap-adjusted misspecification and is an extension of Liu et al. (2023). When the underlying reward function is not linear, existing linear bandits work usually relies on a uniform…

Machine Learning · Computer Science 2025-01-10 Chong Liu , Dan Qiao , Ming Yin , Ilija Bogunovic , Yu-Xiang Wang

We study an extension of the classic stochastic multi-armed bandit problem which involves multiple plays and Markovian rewards in the rested bandits setting. In order to tackle this problem we consider an adaptive allocation rule which at…

Statistics Theory · Mathematics 2020-07-15 Vrettos Moulos

We study the regret of Thompson sampling (TS) algorithms for exponential family bandits, where the reward distribution is from a one-dimensional exponential family, which covers many common reward distributions including Bernoulli,…

Machine Learning · Statistics 2022-06-09 Tianyuan Jin , Pan Xu , Xiaokui Xiao , Anima Anandkumar

We consider a variant of the classic multi-armed bandit problem where the expected reward of each arm is a function of an unknown parameter. The arms are divided into different groups, each of which has a common parameter. Therefore, when…

Machine Learning · Computer Science 2018-02-23 Zhiyang Wang , Ruida Zhou , Cong Shen

This paper introduces and addresses a wide class of stochastic bandit problems where the function mapping the arm to the corresponding reward exhibits some known structural properties. Most existing structures (e.g. linear, Lipschitz,…

Machine Learning · Statistics 2017-11-02 Richard Combes , Stefan Magureanu , Alexandre Proutiere

We consider the problem of learning in single-player and multiplayer multiarmed bandit models. Bandit problems are classes of online learning problems that capture exploration versus exploitation tradeoffs. In a multiarmed bandit model,…

Machine Learning · Statistics 2016-12-02 Naumaan Nayyar , Dileep Kalathil , Rahul Jain

We describe a novel algorithm for noisy global optimisation and continuum-armed bandits, with good convergence properties over any continuous reward function having finitely many polynomial maxima. Over such functions, our algorithm…

Statistics Theory · Mathematics 2015-09-30 Adam D. Bull

We study bandit learning in matching markets, where players and arms constitute the two market sides, and the players' utilities are linear in the arm contexts. In each round, new arms arrive with observable contexts. Then, the algorithm…

Machine Learning · Computer Science 2026-05-28 Shiyun Lin , Simon Mauras , Vianney Perchet , Nadav Merlis