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Related papers: Variance-Aware Sparse Linear Bandits

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In this paper, we revisit the regret minimization problem in sparse stochastic contextual linear bandits, where feature vectors may be of large dimension $d$, but where the reward function depends on a few, say $s_0\ll d$, of these features…

Machine Learning · Statistics 2022-06-22 Kaito Ariu , Kenshi Abe , Alexandre Proutière

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

High-dimensional linear bandits with low-dimensional structure have received considerable attention in recent studies due to their practical significance. The most common structure in the literature is sparsity. However, it may not be…

Machine Learning · Statistics 2026-01-01 Nam Phuong Tran , The Anh Ta , Debmalya Mandal , Long Tran-Thanh

We consider the adversarial linear contextual bandit problem, where the loss vectors are selected fully adversarially and the per-round action set (i.e. the context) is drawn from a fixed distribution. Existing methods for this problem…

Machine Learning · Computer Science 2023-09-06 Haolin Liu , Chen-Yu Wei , Julian Zimmert

We study the linear contextual bandit problem with finite action sets. When the problem dimension is $d$, the time horizon is $T$, and there are $n \leq 2^{d/2}$ candidate actions per time period, we (1) show that the minimax expected…

Machine Learning · Statistics 2020-08-20 Yingkai Li , Yining Wang , Yuan Zhou

This paper addresses the problem of learning to sparsify stochastic linear bandits, where a decision-maker sequentially selects actions from a high-dimensional space subject to a sparsity constraint on the number of nonzero elements in the…

Machine Learning · Computer Science 2026-05-12 Zhengmiao Wang , Ming Chi , Zhi-Wei Liu , Lintao Ye , Carla Fabiana Chiasserini

Adapting to a priori unknown noise level is a very important but challenging problem in sequential decision-making as efficient exploration typically requires knowledge of the noise level, which is often loosely specified. We report…

Machine Learning · Statistics 2024-06-11 Kwang-Sung Jun , Jungtaek Kim

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

Linear bandit algorithms yield $\tilde{\mathcal{O}}(n\sqrt{T})$ pseudo-regret bounds on compact convex action sets $\mathcal{K}\subset\mathbb{R}^n$ and two types of structural assumptions lead to better pseudo-regret bounds. When…

Machine Learning · Computer Science 2021-03-11 Thomas Kerdreux , Christophe Roux , Alexandre d'Aspremont , Sebastian Pokutta

This paper investigates the problem of non-stationary linear bandits, where the unknown regression parameter is evolving over time. Existing studies develop various algorithms and show that they enjoy an…

Machine Learning · Computer Science 2021-12-23 Peng Zhao , Lijun Zhang , Yuan Jiang , Zhi-Hua Zhou

We study the linear contextual bandit problem in the presence of adversarial corruption, where the interaction between the player and a possibly infinite decision set is contaminated by an adversary that can corrupt the reward up to a…

Machine Learning · Computer Science 2021-10-26 Heyang Zhao , Dongruo Zhou , Quanquan Gu

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 revisit the study of optimal regret rates in bandit combinatorial optimization---a fundamental framework for sequential decision making under uncertainty that abstracts numerous combinatorial prediction problems. We prove that the…

Machine Learning · Computer Science 2017-02-27 Alon Cohen , Tamir Hazan , Tomer Koren

We study stochastic multi-armed bandits under simultaneous constraints on space and adaptivity: the learner interacts with the environment in $B$ batches and has only $W$ bits of persistent memory. Prior work shows that each constraint…

Machine Learning · Computer Science 2026-03-31 Ruiyuan Huang , Zicheng Lyu , Xiaoyi Zhu , Zengfeng Huang

Contextual bandit with linear reward functions is among one of the most extensively studied models in bandit and online learning research. Recently, there has been increasing interest in designing \emph{locally private} linear contextual…

Machine Learning · Statistics 2024-04-16 Jiachun Li , David Simchi-Levi , Yining Wang

We consider a linear stochastic bandit problem where the dimension $K$ of the unknown parameter $\theta$ is larger than the sampling budget $n$. In such cases, it is in general impossible to derive sub-linear regret bounds since usual…

Statistics Theory · Mathematics 2012-05-23 Alexandra Carpentier , Rémi Munos

In this paper, we consider the multi-armed bandit problem with high-dimensional features. First, we prove a minimax lower bound, $\mathcal{O}\big((\log d)^{\frac{\alpha+1}{2}}T^{\frac{1-\alpha}{2}}+\log T\big)$, for the cumulative regret,…

Machine Learning · Computer Science 2021-09-27 Ke Li , Yun Yang , Naveen N. Narisetty

We give novel algorithms for multi-task and lifelong linear bandits with shared representation. Specifically, we consider the setting where we play $M$ linear bandits with dimension $d$, each for $T$ rounds, and these $M$ bandit tasks share…

Machine Learning · Computer Science 2022-03-30 Jiaqi Yang , Qi Lei , Jason D. Lee , Simon S. Du

We initiate the study of learning in contextual bandits with the help of loss predictors. The main question we address is whether one can improve over the minimax regret $\mathcal{O}(\sqrt{T})$ for learning over $T$ rounds, when the total…

Machine Learning · Computer Science 2020-10-16 Chen-Yu Wei , Haipeng Luo , Alekh Agarwal

We study the setting of optimizing with bandit feedback with additional prior knowledge provided to the learner in the form of an initial hint of the optimal action. We present a novel algorithm for stochastic linear bandits that uses this…

Machine Learning · Computer Science 2022-03-09 Ashok Cutkosky , Chris Dann , Abhimanyu Das , Qiuyi , Zhang