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Related papers: Regret Lower Bounds in Multi-agent Multi-armed Ban…

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We consider the problem where M agents collaboratively interact with an instance of a stochastic K-armed contextual bandit, where K>>M. The goal of the agents is to simultaneously minimize the cumulative regret over all the agents over a…

Machine Learning · Computer Science 2022-11-16 Jiabin Lin , Shana Moothedath

We study the optimal batch-regret tradeoff for batch linear contextual bandits. For any batch number $M$, number of actions $K$, time horizon $T$, and dimension $d$, we provide an algorithm and prove its regret guarantee, which, due to…

Machine Learning · Computer Science 2022-10-18 Zihan Zhang , Xiangyang Ji , Yuan Zhou

Multi-armed bandit problems are considered as a paradigm of the trade-off between exploring the environment to find profitable actions and exploiting what is already known. In the stationary case, the distributions of the rewards do not…

Statistics Theory · Mathematics 2008-12-18 Aurélien Garivier , Eric Moulines

We consider a situation where an agent has $T$ ressources to be allocated to a larger number $N$ of actions. Each action can be completed at most once and results in a stochastic reward with unknown mean. The goal of the agent is to…

Statistics Theory · Mathematics 2020-11-04 Solenne Gaucher

Dueling bandits are widely used to model preferential feedback prevalent in many applications such as recommendation systems and ranking. In this paper, we study the Borda regret minimization problem for dueling bandits, which aims to…

Machine Learning · Computer Science 2023-09-27 Yue Wu , Tao Jin , Hao Lou , Farzad Farnoud , Quanquan Gu

We study a distributed multi-armed bandit (MAB) problem over arm erasure channels, motivated by the increasing adoption of MAB algorithms over communication-constrained networks. In this setup, the learner communicates the chosen arm to…

Machine Learning · Computer Science 2026-01-21 Merve Karakas , Osama Hanna , Lin F. Yang , Christina Fragouli

In this paper, we study the problem of stochastic linear bandits with finite action sets. Most of existing work assume the payoffs are bounded or sub-Gaussian, which may be violated in some scenarios such as financial markets. To settle…

Machine Learning · Computer Science 2020-04-29 Bo Xue , Guanghui Wang , Yimu Wang , Lijun Zhang

This paper considers two fundamental sequential decision-making problems: the problem of prediction with expert advice and the multi-armed bandit problem. We focus on stochastic regimes in which an adversary may corrupt losses, and we…

Machine Learning · Statistics 2021-09-24 Shinji Ito

In this paper, we consider the stochastic multi-armed bandits problem with adversarial corruptions, where the random rewards of the arms are partially modified by an adversary to fool the algorithm. We apply the policy gradient algorithm…

Machine Learning · Computer Science 2025-02-21 Jiayuan Liu , Siwei Wang , Zhixuan Fang

In this paper we consider the contextual multi-armed bandit problem for linear payoffs under a risk-averse criterion. At each round, contexts are revealed for each arm, and the decision maker chooses one arm to pull and receives the…

Machine Learning · Computer Science 2022-06-28 Yifan Lin , Yuhao Wang , Enlu Zhou

We study a new type of K-armed bandit problem where the expected return of one arm may depend on the returns of other arms. We present a new algorithm for this general class of problems and show that under certain circumstances it is…

Machine Learning · Computer Science 2014-11-12 Tor Lattimore , Remi Munos

In this paper, we study the collaborative learning model, which concerns the tradeoff between parallelism and communication overhead in multi-agent multi-armed bandits. For regret minimization in multi-armed bandits, we present the first…

Machine Learning · Computer Science 2023-12-22 Nikolai Karpov , Qin Zhang

Non-stationary multi-armed bandits enable agents to adapt to changing environments by incorporating mechanisms to detect and respond to shifts in reward distributions, making them well-suited for dynamic settings. However, existing…

Machine Learning · Computer Science 2025-09-19 Shaoang Li , Jian Li

The multi-armed bandit is a concise model for the problem of iterated decision-making under uncertainty. In each round, a gambler must pull one of $K$ arms of a slot machine, without any foreknowledge of their payouts, except that they are…

Data Structures and Algorithms · Computer Science 2007-05-23 Varsha Dani , Thomas P. Hayes

We study the multi-armed bandit problem where the rewards are realizations of general non-stationary stochastic processes, a setting that generalizes many existing lines of work and analyses. In particular, we present a theoretical analysis…

Machine Learning · Computer Science 2020-09-04 Corinna Cortes , Giulia DeSalvo , Vitaly Kuznetsov , Mehryar Mohri , Scott Yang

This paper initiates the study of data-dependent regret bounds in constrained MAB settings. These bounds depend on the sequence of losses that characterize the problem instance. Thus, they can be much smaller than classical…

Machine Learning · Computer Science 2025-06-24 Gianmarco Genalti , Francesco Emanuele Stradi , Matteo Castiglioni , Alberto Marchesi , Nicola Gatti

Given a multi-armed bandit problem it may be desirable to achieve a smaller-than-usual worst-case regret for some special actions. I show that the price for such unbalanced worst-case regret guarantees is rather high. Specifically, if an…

Machine Learning · Computer Science 2015-11-03 Tor Lattimore

Regret bounds in online learning compare the player's performance to $L^*$, the optimal performance in hindsight with a fixed strategy. Typically such bounds scale with the square root of the time horizon $T$. The more refined concept of…

Machine Learning · Computer Science 2018-02-12 Zeyuan Allen-Zhu , Sébastien Bubeck , Yuanzhi Li

We study dynamic regret minimization in unconstrained adversarial linear bandit problems. In this setting, a learner must minimize the cumulative loss relative to an arbitrary sequence of comparators…

Machine Learning · Computer Science 2026-03-30 Alberto Rumi , Andrew Jacobsen , Nicolò Cesa-Bianchi , Fabio Vitale

In bandit settings, optimizing long-term regret metrics requires exploration, which corresponds to sometimes taking myopically sub-optimal actions. When a long-lived principal merely recommends actions to be executed by a sequence of…

Computer Science and Game Theory · Computer Science 2026-02-25 Ramya Ramalingam , Osbert Bastani , Aaron Roth