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Related papers: Structured Stochastic Linear Bandits

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We define the problem of linear Contextual Stochastic Shortest Path (CSSP), where at the beginning of each episode, the learner observes an adversarially chosen context that determines the MDP through a fixed but unknown linear function.…

Machine Learning · Computer Science 2025-11-18 Dor Polikar , Alon Cohen

This paper studies the stochastic linear bandit problem, where a decision-maker chooses actions from possibly time-dependent sets of vectors in $\mathbb{R}^d$ and receives noisy rewards. The objective is to minimize regret, the difference…

Machine Learning · Computer Science 2023-04-24 Nima Hamidi , Mohsen Bayati

We study the problem of stochastic contextual bandits in the agnostic setting, where the goal is to compete with the best policy in a given class without assuming realizability or imposing model restrictions on losses or rewards. In this…

Machine Learning · Statistics 2026-04-06 Samuel Girard , Aurelien Bibaut , Arthur Gretton , Nathan Kallus , Houssam Zenati

We consider the stochastic linear contextual bandit problem with high-dimensional features. We analyze the Thompson sampling algorithm using special classes of sparsity-inducing priors (e.g., spike-and-slab) to model the unknown parameter…

Machine Learning · Statistics 2023-01-31 Sunrit Chakraborty , Saptarshi Roy , Ambuj Tewari

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

The linear contextual bandit literature is mostly focused on the design of efficient learning algorithms for a given representation. However, a contextual bandit problem may admit multiple linear representations, each one with different…

Machine Learning · Computer Science 2021-04-09 Matteo Papini , Andrea Tirinzoni , Marcello Restelli , Alessandro Lazaric , Matteo Pirotta

We study the adversarial kernel bandit problem, in which the loss at each round is induced by an arbitrary bounded element of a reproducing kernel Hilbert space (RKHS). We propose an exponential-weights algorithm built on a regularized…

Machine Learning · Computer Science 2026-05-27 Yu-Jie Zhang , Hao Qiu , Jonathan Scarlett , Kevin Jamieson

We consider a safe optimization problem with bandit feedback in which an agent sequentially chooses actions and observes responses from the environment, with the goal of maximizing an arbitrary function of the response while respecting…

Machine Learning · Computer Science 2023-05-02 Spencer Hutchinson , Berkay Turan , Mahnoosh Alizadeh

We present simple and efficient algorithms for the batched stochastic multi-armed bandit and batched stochastic linear bandit problems. We prove bounds for their expected regrets that improve over the best-known regret bounds for any number…

Data Structures and Algorithms · Computer Science 2020-02-19 Hossein Esfandiari , Amin Karbasi , Abbas Mehrabian , Vahab Mirrokni

We study an interesting variant of the stochastic multi-armed bandit problem, called the Fair-SMAB problem, where each arm is required to be pulled for at least a given fraction of the total available rounds. We investigate the interplay…

Machine Learning · Computer Science 2020-02-06 Vishakha Patil , Ganesh Ghalme , Vineet Nair , Y. Narahari

We consider the problem of adversarial (non-stochastic) online learning with partial information feedback, where at each round, a decision maker selects an action from a finite set of alternatives. We develop a black-box approach for such…

Machine Learning · Computer Science 2021-07-28 Thodoris Lykouris , Karthik Sridharan , Eva Tardos

We consider a partial-feedback variant of the well-studied online PCA problem where a learner attempts to predict a sequence of $d$-dimensional vectors in terms of a quadratic loss, while only having limited feedback about the environment's…

Machine Learning · Computer Science 2019-02-11 Wojciech Kotłowski , Gergely Neu

This paper studies the one-shot behavior of no-regret algorithms for stochastic bandits. Although many algorithms are known to be asymptotically optimal with respect to the expected regret, over a single run, their pseudo-regret seems to…

Machine Learning · Computer Science 2023-12-01 Victor Boone

We explore a stochastic contextual linear bandit problem where the agent observes a noisy, corrupted version of the true context through a noise channel with an unknown noise parameter. Our objective is to design an action policy that can…

Machine Learning · Computer Science 2024-03-26 Sharu Theresa Jose , Shana Moothedath

We study the recovering bandits problem, a variant of the stochastic multi-armed bandit problem where the expected reward of each arm varies according to some unknown function of the time since the arm was last played. While being a natural…

Machine Learning · Statistics 2019-11-01 Ciara Pike-Burke , Steffen Grünewälder

We develop a new approach to obtaining high probability regret bounds for online learning with bandit feedback against an adaptive adversary. While existing approaches all require carefully constructing optimistic and biased loss…

Machine Learning · Computer Science 2020-11-02 Chung-Wei Lee , Haipeng Luo , Chen-Yu Wei , Mengxiao 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

We introduce a new stochastic smoothing perspective to study adversarial contextual bandit problems. We propose a general algorithm template that represents random perturbation based algorithms and identify several perturbation…

Machine Learning · Statistics 2019-06-12 Young Hun Jung , Ambuj Tewari

We consider the problem of controlling an unknown linear dynamical system in the presence of (nonstochastic) adversarial perturbations and adversarial convex loss functions. In contrast to classical control, the a priori determination of an…

Machine Learning · Computer Science 2020-01-22 Elad Hazan , Sham M. Kakade , Karan Singh

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