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Related papers: Linear bandits with polylogarithmic minimax regret

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Policy regret is a well established notion of measuring the performance of an online learning algorithm against an adaptive adversary. We study restrictions on the adversary that enable efficient minimization of the \emph{complete policy…

Machine Learning · Statistics 2022-04-26 Dhruv Malik , Yuanzhi Li , Aarti Singh

Contextual bandits are a central framework for sequential decision-making, with applications ranging from recommendation systems to clinical trials. While nonparametric methods can flexibly model complex reward structures, they suffer from…

Statistics Theory · Mathematics 2026-01-01 Wanteng Ma , T. Tony Cai

We analyse adversarial bandit convex optimisation with an adversary that is restricted to playing functions of the form $f_t(x) = g_t(\langle x, \theta\rangle)$ for convex $g_t : \mathbb R \to \mathbb R$ and unknown $\theta \in \mathbb R^d$…

Machine Learning · Computer Science 2021-06-08 Tor Lattimore

We study stochastic linear bandits with heavy-tailed rewards, where the rewards have a finite $(1+\epsilon)$-absolute central moment bounded by $\upsilon$ for some $\epsilon \in (0,1]$. We improve both upper and lower bounds on the minimax…

Machine Learning · Computer Science 2026-01-28 Artin Tajdini , Jonathan Scarlett , Kevin Jamieson

We present improved algorithms with worst-case regret guarantees for the stochastic linear bandit problem. The widely used "optimism in the face of uncertainty" principle reduces a stochastic bandit problem to the construction of a…

Machine Learning · Statistics 2024-09-06 Hamish Flynn , David Reeb , Melih Kandemir , Jan Peters

We propose and analyze TRAiL (Tangential Randomization in Linear Bandits), a computationally efficient regret-optimal forced exploration algorithm for linear bandits on action sets that are sublevel sets of strongly convex functions. TRAiL…

Machine Learning · Statistics 2024-11-20 Arda Güçlü , Subhonmesh Bose

We study the benefits of sparsity in nonparametric contextual bandit problems, in which the set of candidate features is countably or uncountably infinite. Our contribution is two-fold. First, using a novel reduction to sequences of…

Machine Learning · Statistics 2026-01-16 Hamish Flynn , Julia Olkhovskaya , Paul Rognon-Vael

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 stochastic shortest path problem with adversarial costs and known transition, and show that the minimax regret is $\widetilde{O}(\sqrt{DT^\star K})$ and $\widetilde{O}(\sqrt{DT^\star SA K})$ for the full-information setting and…

Machine Learning · Computer Science 2021-06-23 Liyu Chen , Haipeng Luo , Chen-Yu Wei

The problem of regret minimization for online adaptive control of linear-quadratic systems is studied. In this problem, the true system transition parameters (matrices $A$ and $B$) are unknown, and the objective is to design and analyze…

Optimization and Control · Mathematics 2022-10-31 Mohammad Akbari , Bahman Gharesifard , Tamas Linder

We consider a stochastic linear bandit problem in which the rewards are not only subject to random noise, but also adversarial attacks subject to a suitable budget $C$ (i.e., an upper bound on the sum of corruption magnitudes across the…

Machine Learning · Statistics 2020-10-29 Ilija Bogunovic , Arpan Losalka , Andreas Krause , Jonathan Scarlett

This paper studies semiparametric contextual bandits, a generalization of the linear stochastic bandit problem where the reward for an action is modeled as a linear function of known action features confounded by an non-linear…

Machine Learning · Statistics 2018-07-17 Akshay Krishnamurthy , Zhiwei Steven Wu , Vasilis Syrgkanis

We consider a multi-armed bandit problem where payoffs are a linear function of an observed stochastic contextual variable. In the scenario where there exists a gap between optimal and suboptimal rewards, several algorithms have been…

Data Structures and Algorithms · Computer Science 2014-07-08 José Bento , Stratis Ioannidis , S. Muthukrishnan , Jinyun Yan

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 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

In sparse linear bandits, a learning agent sequentially selects an action and receive reward feedback, and the reward function depends linearly on a few coordinates of the covariates of the actions. This has applications in many real-world…

Machine Learning · Statistics 2023-11-21 Kyoungseok Jang , Chicheng Zhang , Kwang-Sung Jun

We propose the first regret-based approach to the Graphical Bilinear Bandits problem, where $n$ agents in a graph play a stochastic bilinear bandit game with each of their neighbors. This setting reveals a combinatorial NP-hard problem that…

Machine Learning · Computer Science 2022-10-13 Geovani Rizk , Igor Colin , Albert Thomas , Rida Laraki , Yann Chevaleyre

We study a time-varying Bayesian optimization problem with bandit feedback, where the reward function belongs to a Reproducing Kernel Hilbert Space (RKHS). We approach the problem via an upper-confidence bound Gaussian Process algorithm,…

Optimization and Control · Mathematics 2025-10-27 Eliabelle Mauduit , Eloïse Berthier , Andrea Simonetto

We study the problem of expert advice under partial bandit feedback setting and create a sequential minimax optimal algorithm. Our algorithm works with a more general partial monitoring setting, where, in contrast to the classical bandit…

Machine Learning · Computer Science 2022-04-15 Kaan Gokcesu , Hakan Gokcesu

We study a collaborative multi-agent stochastic linear bandit setting, where $N$ agents that form a network communicate locally to minimize their overall regret. In this setting, each agent has its own linear bandit problem (its own reward…

Machine Learning · Computer Science 2022-05-16 Ahmadreza Moradipari , Mohammad Ghavamzadeh , Mahnoosh Alizadeh
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