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Related papers: Nonstochastic Bandits with Infinitely Many Experts

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We consider the restless Markov bandit problem, in which the state of each arm evolves according to a Markov process independently of the learner's actions. We suggest an algorithm that after $T$ steps achieves $\tilde{O}(\sqrt{T})$ regret…

Machine Learning · Computer Science 2012-10-23 Ronald Ortner , Daniil Ryabko , Peter Auer , Rémi Munos

We study high-dimensional multi-armed contextual bandits with batched feedback where the $T$ steps of online interactions are divided into $L$ batches. In specific, each batch collects data according to a policy that depends on previous…

Machine Learning · Statistics 2023-11-27 Jianqing Fan , Zhaoran Wang , Zhuoran Yang , Chenlu Ye

We study the $K$-armed contextual dueling bandit problem, a sequential decision making setting in which the learner uses contextual information to make two decisions, but only observes \emph{preference-based feedback} suggesting that one…

Machine Learning · Computer Science 2021-11-25 Aadirupa Saha , Akshay Krishnamurthy

We consider a special case of bandit problems, named batched bandits, in which an agent observes batches of responses over a certain time period. Unlike previous work, we consider a more practically relevant batch-centric scenario of batch…

Machine Learning · Computer Science 2023-04-04 Danil Provodin , Pratik Gajane , Mykola Pechenizkiy , Maurits Kaptein

We consider a variation on the problem of prediction with expert advice, where new forecasters that were unknown until then may appear at each round. As often in prediction with expert advice, designing an algorithm that achieves…

Machine Learning · Statistics 2017-09-01 Jaouad Mourtada , Odalric-Ambrym Maillard

Designing efficient general-purpose contextual bandit algorithms that work with large -- or even continuous -- action spaces would facilitate application to important scenarios such as information retrieval, recommendation systems, and…

Machine Learning · Computer Science 2022-07-14 Yinglun Zhu , Paul Mineiro

We study stochastic linear bandits where, in each round, the learner receives a set of actions (i.e., feature vectors), from which it chooses an element and obtains a stochastic reward. The expected reward is a fixed but unknown linear…

Machine Learning · Computer Science 2024-06-04 Tianyuan Jin , Kyoungseok Jang , Nicolò Cesa-Bianchi

We study nonstochastic bandits and experts in a delayed setting where delays depend on both time and arms. While the setting in which delays only depend on time has been extensively studied, the arm-dependent delay setting better captures…

Machine Learning · Computer Science 2021-12-22 Dirk van der Hoeven , Nicolò Cesa-Bianchi

We consider the infinitely many-armed bandit problem with rotting rewards, where the mean reward of an arm decreases at each pull of the arm according to an arbitrary trend with maximum rotting rate $\varrho=o(1)$. We show that this…

Machine Learning · Computer Science 2023-12-19 Jung-hun Kim , Milan Vojnovic , Se-Young Yun

We study the classic problem of prediction with expert advice under bandit feedback. Our model assumes that one action, corresponding to the learner's abstention from play, has no reward or loss on every trial. We propose the CBA algorithm,…

Machine Learning · Computer Science 2024-11-13 Stephen Pasteris , Alberto Rumi , Maximilian Thiessen , Shota Saito , Atsushi Miyauchi , Fabio Vitale , Mark Herbster

We study the constrained variant of the \emph{multi-armed bandit} (MAB) problem, in which the learner aims not only at minimizing the total loss incurred during the learning dynamic, but also at controlling the violation of multiple…

Machine Learning · Computer Science 2026-02-17 Francesco Emanuele Stradi , Kalana Kalupahana , Matteo Castiglioni , Alberto Marchesi , Nicola Gatti

We consider the nonstochastic multi-agent multi-armed bandit problem with agents collaborating via a communication network with delays. We show a lower bound for individual regret of all agents. We show that with suitable regularizers and…

Machine Learning · Statistics 2023-10-24 Jialin Yi , Milan Vojnović

We study how representation learning can improve the efficiency of bandit problems. We study the setting where we play $T$ linear bandits with dimension $d$ concurrently, and these $T$ bandit tasks share a common $k (\ll d)$ dimensional…

Machine Learning · Computer Science 2021-05-06 Jiaqi Yang , Wei Hu , Jason D. Lee , Simon S. Du

We study the kernelized bandit problem, that involves designing an adaptive strategy for querying a noisy zeroth-order-oracle to efficiently learn about the optimizer of an unknown function $f$ with a norm bounded by $M<\infty$ in a…

Machine Learning · Computer Science 2022-03-15 Shubhanshu Shekhar , Tara Javidi

Combinatorial multi-armed bandits provide a fundamental online decision-making environment where a decision-maker interacts with an environment across $T$ time steps, each time selecting an action and learning the cost of that action. The…

Machine Learning · Computer Science 2026-04-13 Gerdus Benadè , Rathish Das , Thomas Lavastida

This work addresses the mediator feedback problem, a bandit game where the decision set consists of a number of policies, each associated with a probability distribution over a common space of outcomes. Upon choosing a policy, the learner…

Machine Learning · Computer Science 2024-02-19 Khaled Eldowa , Nicolò Cesa-Bianchi , Alberto Maria Metelli , Marcello Restelli

We develop a meta-learning framework for simple regret minimization in bandits. In this framework, a learning agent interacts with a sequence of bandit tasks, which are sampled i.i.d.\ from an unknown prior distribution, and learns its…

Machine Learning · Computer Science 2023-07-06 Mohammadjavad Azizi , Branislav Kveton , Mohammad Ghavamzadeh , Sumeet Katariya

We study stochastic structured bandits for minimizing regret. The fact that the popular optimistic algorithms do not achieve the asymptotic instance-dependent regret optimality (asymptotic optimality for short) has recently alluded…

Machine Learning · Computer Science 2020-10-26 Kwang-Sung Jun , Chicheng Zhang

This paper proposes a linear bandit algorithm that is adaptive to environments at two different levels of hierarchy. At the higher level, the proposed algorithm adapts to a variety of types of environments. More precisely, it achieves…

Machine Learning · Computer Science 2023-02-27 Shinji Ito , Kei Takemura

Past research on interactive decision making problems (bandits, reinforcement learning, etc.) mostly focuses on the minimax regret that measures the algorithm's performance on the hardest instance. However, an ideal algorithm should adapt…

Machine Learning · Computer Science 2023-06-13 Kefan Dong , Tengyu Ma