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Related papers: Linear bandits with polylogarithmic minimax regret

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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

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

The stochastic linear bandit problem proceeds in rounds where at each round the algorithm selects a vector from a decision set after which it receives a noisy linear loss parameterized by an unknown vector. The goal in such a problem is to…

Machine Learning · Statistics 2016-06-21 Nicholas Johnson , Vidyashankar Sivakumar , Arindam Banerjee

In this work, we develop linear bandit algorithms that automatically adapt to different environments. By plugging a novel loss estimator into the optimization problem that characterizes the instance-optimal strategy, our first algorithm not…

Machine Learning · Computer Science 2021-06-15 Chung-Wei Lee , Haipeng Luo , Chen-Yu Wei , Mengxiao Zhang , Xiaojin Zhang

In this paper we propose a novel experimental design-based algorithm to minimize regret in online stochastic linear and combinatorial bandits. While existing literature tends to focus on optimism-based algorithms--which have been shown to…

Machine Learning · Computer Science 2021-03-02 Andrew Wagenmaker , Julian Katz-Samuels , Kevin Jamieson

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

This paper explores a new form of the linear bandit problem in which the algorithm receives the usual stochastic rewards as well as stochastic feedback about which features are relevant to the rewards, the latter feedback being the novel…

Machine Learning · Computer Science 2019-03-13 Urvashi Oswal , Aniruddha Bhargava , Robert Nowak

We present a non-asymptotic lower bound on the eigenspectrum of the design matrix generated by any linear bandit algorithm with sub-linear regret when the action set has well-behaved curvature. Specifically, we show that the minimum…

Machine Learning · Computer Science 2023-01-10 Debangshu Banerjee , Avishek Ghosh , Sayak Ray Chowdhury , Aditya Gopalan

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 contextual bandits with low-rank structure where, in each round, if the (context, arm) pair $(i,j)\in [m]\times [n]$ is selected, the learner observes a noisy sample of the $(i,j)$-th entry of an unknown low-rank reward matrix.…

Machine Learning · Computer Science 2024-07-08 Yassir Jedra , William Réveillard , Stefan Stojanovic , Alexandre Proutiere

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

We study the control of an \emph{unknown} linear dynamical system under general convex costs. The objective is minimizing regret vs. the class of disturbance-feedback-controllers, which encompasses all stabilizing…

Machine Learning · Computer Science 2020-10-30 Orestis Plevrakis , Elad Hazan

We study regret minimization in a stochastic multi-armed bandit setting and establish a fundamental trade-off between the regret suffered under an algorithm, and its statistical robustness. Considering broad classes of underlying arms'…

Machine Learning · Computer Science 2020-06-23 Kumar Ashutosh , Jayakrishnan Nair , Anmol Kagrecha , Krishna Jagannathan

We study online learning with bandit feedback (i.e. learner has access to only zeroth-order oracle) where cost/reward functions $\f_t$ admit a "pseudo-1d" structure, i.e. $\f_t(\w) = \loss_t(\pred_t(\w))$ where the output of $\pred_t$ is…

Machine Learning · Computer Science 2021-02-16 Aadirupa Saha , Nagarajan Natarajan , Praneeth Netrapalli , Prateek Jain

In this work we consider the problem of regret minimization for logistic bandits. The main challenge of logistic bandits is reducing the dependence on a potentially large problem dependent constant $\kappa$ that can at worst scale…

Machine Learning · Statistics 2022-02-08 Blake Mason , Kwang-Sung Jun , Lalit Jain

We study bandit model selection in stochastic environments. Our approach relies on a meta-algorithm that selects between candidate base algorithms. We develop a meta-algorithm-base algorithm abstraction that can work with general classes of…

Machine Learning · Computer Science 2022-12-06 Aldo Pacchiano , My Phan , Yasin Abbasi-Yadkori , Anup Rao , Julian Zimmert , Tor Lattimore , Csaba Szepesvari

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 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 present a new anytime algorithm that achieves near-optimal regret for any instance of finite stochastic partial monitoring. In particular, the new algorithm achieves the minimax regret, within logarithmic factors, for both "easy" and…

Machine Learning · Computer Science 2012-07-03 Gabor Bartok , Navid Zolghadr , Csaba Szepesvari

We study a stochastic convex bandit problem where the subgaussian noise parameter is assumed to decrease linearly as the learner selects actions closer and closer to the minimizer of the convex loss function. Accordingly, we propose a…

Optimization and Control · Mathematics 2025-01-22 Jingxin Zhan , Yuchen Xin , Kaicheng Jin , Zhihua Zhang