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In pure-exploration problems, information is gathered sequentially to answer a question on the stochastic environment. While best-arm identification for linear bandits has been extensively studied in recent years, few works have been…

Machine Learning · Statistics 2022-06-10 Marc Jourdan , Rémy Degenne

In the infinite-armed bandit problem, each arm's average reward is sampled from an unknown distribution, and each arm can be sampled further to obtain noisy estimates of the average reward of that arm. Prior work focuses on identifying the…

Machine Learning · Computer Science 2022-11-04 Yifei Wang , Tavor Baharav , Yanjun Han , Jiantao Jiao , David Tse

We consider a good arm identification problem in a stochastic bandit setting with multi-objectives, where each arm $i \in [K]$ is associated with a distribution $D_i$ defined over $R^M$. For each round $t$, the player pulls an arm $i_t$ and…

Machine Learning · Computer Science 2025-06-30 Xuanke Jiang , Sherief Hashima , Kohei Hatano , Eiji Takimoto

We consider the question introduced by \cite{Mason2020} of identifying all the $\varepsilon$-optimal arms in a finite stochastic multi-armed bandit with Gaussian rewards. We give two lower bounds on the sample complexity of any algorithm…

Machine Learning · Statistics 2022-04-07 Aymen Al Marjani , Tomáš Kocák , Aurélien Garivier

The best arm identification problem (BEST-1-ARM) is the most basic pure exploration problem in stochastic multi-armed bandits. The problem has a long history and attracted significant attention for the last decade. However, we do not yet…

Machine Learning · Computer Science 2016-05-30 Lijie Chen , Jian Li

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

This paper investigates a hitherto unaddressed aspect of best arm identification (BAI) in stochastic multi-armed bandits in the fixed-confidence setting. Two key metrics for assessing bandit algorithms are computational efficiency and…

Machine Learning · Statistics 2023-06-26 Arpan Mukherjee , Ali Tajer

This work investigates the problem of best arm identification for multi-agent multi-armed bandits. We consider $N$ agents grouped into $M$ clusters, where each cluster solves a stochastic bandit problem. The mapping between agents and…

Machine Learning · Computer Science 2025-05-16 Yash , Nikhil Karamchandani , Avishek Ghosh

We consider the best arm identification problem in the stochastic multi-armed bandit framework where each arm has a tiny probability of realizing large rewards while with overwhelming probability the reward is zero. A key application of…

Machine Learning · Computer Science 2023-03-15 Anirban Bhattacharjee , Sushant Vijayan , Sandeep K Juneja

We investigate the fixed-budget best-arm identification (BAI) problem for linear bandits in a potentially non-stationary environment. Given a finite arm set $\mathcal{X}\subset\mathbb{R}^d$, a fixed budget $T$, and an unpredictable sequence…

Machine Learning · Computer Science 2024-02-16 Zhihan Xiong , Romain Camilleri , Maryam Fazel , Lalit Jain , Kevin Jamieson

We study best-arm identification in stochastic multi-armed bandits under the fixed-confidence setting, focusing on instances with multiple optimal arms. Unlike prior work that addresses the unknown-number-of-optimal-arms case, we consider…

Machine Learning · Computer Science 2026-03-05 Lan V. Truong

We study best-arm identification in stochastic dueling bandits under the sole assumption that a Condorcet winner exists, i.e., an arm that wins each noisy pairwise comparison with probability at least $1/2$. We introduce a new…

Machine Learning · Statistics 2026-03-17 El Mehdi Saad , Victor Thuot , Nicolas Verzelen

We consider a novel stochastic multi-armed bandit problem called {\em good arm identification} (GAI), where a good arm is defined as an arm with expected reward greater than or equal to a given threshold. GAI is a pure-exploration problem…

In this paper, we study a variant of best-arm identification involving elements of risk sensitivity and communication constraints. Specifically, the goal of the learner is to identify the arm with the highest quantile reward, while the…

Machine Learning · Statistics 2025-02-11 Ivan Lau , Jonathan Scarlett

We consider the problem of \textit{best arm identification} with a \textit{fixed budget $T$}, in the $K$-armed stochastic bandit setting, with arms distribution defined on $[0,1]$. We prove that any bandit strategy, for at least one bandit…

Machine Learning · Statistics 2016-05-31 Alexandra Carpentier , Andrea Locatelli

We study a novel pure exploration problem: the $\epsilon$-Thresholding Bandit Problem (TBP) with fixed confidence in stochastic linear bandits. We prove a lower bound for the sample complexity and extend an algorithm designed for Best Arm…

Machine Learning · Statistics 2024-02-16 Eduardo Ochoa Rivera , Ambuj Tewari

The challenge of identifying the best feasible arm within a fixed budget has attracted considerable interest in recent years. However, a notable gap remains in the literature: the exact exponential rate at which the error probability…

Machine Learning · Computer Science 2025-06-04 Jie Bian , Vincent Y. F. Tan

We study the problem of best arm identification in linearly parameterised multi-armed bandits. Given a set of feature vectors $\mathcal{X}\subset\mathbb{R}^d,$ a confidence parameter $\delta$ and an unknown vector $\theta^*,$ the goal is to…

Machine Learning · Computer Science 2020-06-16 Mohammadi Zaki , Avi Mohan , Aditya Gopalan

We study the fixed-budget best-arm identification (BAI) problem in non-stationary linear bandits. Concretely, given a fixed time budget $T\in \mathbb{N}$, finite arm set $\mathcal{X} \subset \mathbb{R}^d$, and a potentially adversarial…

Machine Learning · Statistics 2026-03-12 Leo Maynard-Zhang , Zhihan Xiong , Kevin Jamieson , Maryam Fazel

In this paper we consider the problem of best-arm identification in multi-armed bandits in the fixed confidence setting, where the goal is to identify, with probability $1-\delta$ for some $\delta>0$, the arm with the highest mean reward in…

Machine Learning · Statistics 2021-09-13 Samarth Gupta , Gauri Joshi , Osman Yağan