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Related papers: Stochastic Bandits Robust to Adversarial Attacks

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We study the problem of adversarial combinatorial bandit with a switching cost $\lambda$ for a switch of each selected arm in each round, considering both the bandit feedback and semi-bandit feedback settings. In the oblivious adversarial…

Machine Learning · Statistics 2024-04-03 Yanyan Dong , Vincent Y. F. Tan

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

We study a constrained contextual linear bandit setting, where the goal of the agent is to produce a sequence of policies, whose expected cumulative reward over the course of $T$ rounds is maximum, and each has an expected cost below a…

Machine Learning · Computer Science 2020-06-20 Aldo Pacchiano , Mohammad Ghavamzadeh , Peter Bartlett , Heinrich Jiang

We study finite-armed semiparametric bandits, where each arm's reward combines a linear component with an unknown, potentially adversarial shift. This model strictly generalizes classical linear bandits and reflects complexities common in…

Machine Learning · Statistics 2025-06-18 Seok-Jin Kim , Gi-Soo Kim , Min-hwan Oh

We consider stochastic multi-armed bandits where the expected reward is a unimodal function over partially ordered arms. This important class of problems has been recently investigated in (Cope 2009, Yu 2011). The set of arms is either…

Machine Learning · Computer Science 2014-05-21 Richard Combes , Alexandre Proutiere

In this paper, we consider stochastic multi-armed bandits (MABs) with heavy-tailed rewards, whose $p$-th moment is bounded by a constant $\nu_{p}$ for $1<p\leq2$. First, we propose a novel robust estimator which does not require $\nu_{p}$…

Machine Learning · Computer Science 2021-10-28 Kyungjae Lee , Hongjun Yang , Sungbin Lim , Songhwai Oh

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

The problem of multi-armed bandits (MAB) asks to make sequential decisions while balancing between exploitation and exploration, and have been successfully applied to a wide range of practical scenarios. Various algorithms have been…

Machine Learning · Computer Science 2022-02-24 Xiaojin Zhang , Shuai Li , Weiwen Liu , Shengyu Zhang

We consider the adversarial multi-armed bandit problem under delayed feedback. We analyze variants of the Exp3 algorithm that tune their step-size using only information (about the losses and delays) available at the time of the decisions,…

Machine Learning · Computer Science 2020-10-14 András György , Pooria Joulani

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

We consider the classical stochastic multi-armed bandit but where, from time to time and roughly with frequency $\epsilon$, an extra observation is gathered by the agent for free. We prove that, no matter how small $\epsilon$ is the agent…

Machine Learning · Computer Science 2018-07-11 Rémy Degenne , Evrard Garcelon , Vianney Perchet

We study the multi-armed bandit problem with adversarially chosen delays in the Best-of-Both-Worlds (BoBW) framework, which aims to achieve near-optimal performance in both stochastic and adversarial environments. While prior work has made…

Machine Learning · Computer Science 2025-10-21 Ofir Schlisselberg , Tal Lancewicki , Peter Auer , Yishay Mansour

This paper is in the field of stochastic Multi-Armed Bandits (MABs), i.e. those sequential selection techniques able to learn online using only the feedback given by the chosen option (a.k.a. $arm$). We study a particular case of the rested…

Machine Learning · Statistics 2024-11-28 Marco Fiandri , Alberto Maria Metelli , Francesco Trov`o

In this paper, we consider the problem of sleeping bandits with stochastic action sets and adversarial rewards. In this setting, in contrast to most work in bandits, the actions may not be available at all times. For instance, some products…

Machine Learning · Computer Science 2020-08-11 Aadirupa Saha , Pierre Gaillard , Michal Valko

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

We consider minimisation of dynamic regret in non-stationary bandits with a slowly varying property. Namely, we assume that arms' rewards are stochastic and independent over time, but that the absolute difference between the expected…

Machine Learning · Computer Science 2021-10-26 Ramakrishnan Krishnamurthy , Aditya Gopalan

We consider a stochastic multi-armed bandit setting where reward must be actively queried for it to be observed. We provide tight lower and upper problem-dependent guarantees on both the regret and the number of queries. Interestingly, we…

Machine Learning · Computer Science 2022-10-28 Nadav Merlis , Yonathan Efroni , Shie Mannor

We introduce the factored bandits model, which is a framework for learning with limited (bandit) feedback, where actions can be decomposed into a Cartesian product of atomic actions. Factored bandits incorporate rank-1 bandits as a special…

Machine Learning · Computer Science 2018-10-30 Julian Zimmert , Yevgeny Seldin

We consider the stochastic bandit problem in the sublinear space setting, where one cannot record the win-loss record for all $K$ arms. We give an algorithm using $O(1)$ words of space with regret \[ \sum_{i=1}^{K}\frac{1}{\Delta_i}\log…

Data Structures and Algorithms · Computer Science 2018-05-17 David Liau , Eric Price , Zhao Song , Ger Yang

We develop the first general semi-bandit algorithm that simultaneously achieves $\mathcal{O}(\log T)$ regret for stochastic environments and $\mathcal{O}(\sqrt{T})$ regret for adversarial environments without knowledge of the regime or the…

Machine Learning · Computer Science 2019-09-27 Julian Zimmert , Haipeng Luo , Chen-Yu Wei