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Related papers: On ergodic two-armed bandits

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We study the fixed-confidence best-arm identification problem in unimodal bandits, in which the means of the arms increase with the index of the arm up to their maximum, then decrease. We derive two lower bounds on the stopping time of any…

Machine Learning · Computer Science 2025-05-27 Riccardo Poiani , Marc Jourdan , Emilie Kaufmann , Rémy Degenne

We study bandit best-arm identification with arbitrary and potentially adversarial rewards. A simple random uniform learner obtains the optimal rate of error in the adversarial scenario. However, this type of strategy is suboptimal when the…

Machine Learning · Statistics 2026-04-17 Yasin Abbasi-Yadkori , Peter L. Bartlett , Victor Gabillon , Alan Malek , Michal Valko

We consider a stochastic bandit problem with a possibly infinite number of arms. We write $p^*$ for the proportion of optimal arms and $\Delta$ for the minimal mean-gap between optimal and sub-optimal arms. We characterize the optimal…

Machine Learning · Computer Science 2021-11-08 Rianne de Heide , James Cheshire , Pierre Ménard , Alexandra Carpentier

We consider adversarial multi-armed bandit problems where the learner is allowed to observe losses of a number of arms beside the arm that it actually chose. We study the case where all non-chosen arms reveal their loss with a fixed but…

Machine Learning · Statistics 2026-04-29 Tomáš Kocák , Gergely Neu , Michal Valko

This paper considers the multi-armed thresholding bandit problem -- identifying all arms whose expected rewards are above a predefined threshold via as few pulls (or rounds) as possible -- proposed by Locatelli et al. [2016] recently.…

Machine Learning · Statistics 2017-07-11 Jie Zhong , Yijun Huang , Ji Liu

In multi-armed bandits, the most-explored arms are the most informative, while reward maximization typically pulls only the best arm. We study the tradeoff between identifying arm means accurately and accumulating reward, and present an…

Machine Learning · Computer Science 2026-05-04 Akram Erraqabi , Alessandro Lazaric , Michal Valko , Emma Brunskill , Yun-En Liu

We consider the classic Multi-Armed Bandit setting to understand the exploration/exploitation tradeoffs made by different search heuristics. Since many search heuristics work by comparing different options (in evolutionary algorithms called…

Neural and Evolutionary Computing · Computer Science 2026-04-10 Jasmin Brandt , Barbara Hammer , Timo Kötzing , Jurek Sander

Multi-arm bandits are gaining popularity as they enable real-world sequential decision-making across application areas, including clinical trials, recommender systems, and online decision-making. Consequently, there is an increased desire…

Methodology · Statistics 2023-03-01 Dae Woong Ham , Iavor Bojinov , Michael Lindon , Martin Tingley

We study a sequential resource allocation problem between a fixed number of arms. On each iteration the algorithm distributes a resource among the arms in order to maximize the expected success rate. Allocating more of the resource to a…

Machine Learning · Computer Science 2018-03-29 Yuval Dagan , Koby Crammer

In this paper, we propose a Thompson Sampling algorithm for \emph{unimodal} bandits, where the expected reward is unimodal over the partially ordered arms. To exploit the unimodal structure better, at each step, instead of exploration from…

Machine Learning · Computer Science 2021-06-17 Long Yang , Zhao Li , Zehong Hu , Shasha Ruan , Shijian Li , Gang Pan , Hongyang Chen

We consider a sequential decision-making problem where an agent can take one action at a time and each action has a stochastic temporal extent, i.e., a new action cannot be taken until the previous one is finished. Upon completion, the…

Machine Learning · Computer Science 2020-03-26 P Sharoff , Nishant A. Mehta , Ravi Ganti

We study the best-arm identification problem in linear bandit, where the rewards of the arms depend linearly on an unknown parameter $\theta^*$ and the objective is to return the arm with the largest reward. We characterize the complexity…

Machine Learning · Computer Science 2014-11-05 Marta Soare , Alessandro Lazaric , Rémi Munos

We study the multi-armed bandit problem with arms which are Markov chains with rewards. In the finite-horizon setting, the celebrated Gittins indices do not apply, and the exact solution is intractable. We provide approximation algorithms…

Data Structures and Algorithms · Computer Science 2016-09-14 Will Ma

This paper introduces the informational multi-armed bandit (IMAB) model in which at each round, a player chooses an arm, observes a symbol, and receives an unobserved reward in the form of the symbol's self-information. Thus, the expected…

Information Theory · Computer Science 2022-09-07 Nir Weinberger , Michal Yemini

In a linear stochastic bandit model, each arm is a vector in an Euclidean space and the observed return at each time step is an unknown linear function of the chosen arm at that time step. In this paper, we investigate the problem of…

Machine Learning · Computer Science 2019-10-25 Qiyu Kang , Wee Peng Tay

Classical multi-armed bandit problems use the expected value of an arm as a metric to evaluate its goodness. However, the expected value is a risk-neutral metric. In many applications like finance, one is interested in balancing the…

Machine Learning · Computer Science 2019-06-04 Anmol Kagrecha , Jayakrishnan Nair , Krishna Jagannathan

We propose a novel combinatorial stochastic-greedy bandit (SGB) algorithm for combinatorial multi-armed bandit problems when no extra information other than the joint reward of the selected set of $n$ arms at each time step $t\in [T]$ is…

Machine Learning · Computer Science 2023-12-14 Fares Fourati , Christopher John Quinn , Mohamed-Slim Alouini , Vaneet Aggarwal

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

The Greedy algorithm is the simplest heuristic in sequential decision problem that carelessly takes the locally optimal choice at each round, disregarding any advantages of exploring and/or information gathering. Theoretically, it is known…

Machine Learning · Computer Science 2021-01-05 Matthieu Jedor , Jonathan Louëdec , Vianney Perchet

I study adversarial attacks against stochastic bandit algorithms. At each round, the learner chooses an arm, and a stochastic reward is generated. The adversary strategically adds corruption to the reward, and the learner is only able to…

Machine Learning · Computer Science 2024-03-18 Shiliang Zuo