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Related papers: Adversarial Contextual Bandits Go Kernelized

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Autoregressive processes naturally arise in a large variety of real-world scenarios, including stock markets, sales forecasting, weather prediction, advertising, and pricing. When facing a sequential decision-making problem in such a…

We are interested in a framework of online learning with kernels for low-dimensional but large-scale and potentially adversarial datasets. We study the computational and theoretical performance of online variations of kernel Ridge…

Machine Learning · Statistics 2019-05-30 Rémi Jézéquel , Pierre Gaillard , Alessandro Rudi

We study online reinforcement learning in linear Markov decision processes with adversarial losses and bandit feedback, without prior knowledge on transitions or access to simulators. We introduce two algorithms that achieve improved regret…

Machine Learning · Computer Science 2023-10-19 Haolin Liu , Chen-Yu Wei , Julian Zimmert

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

We study the problem of $K$-armed dueling bandit for both stochastic and adversarial environments, where the goal of the learner is to aggregate information through relative preferences of pair of decisions points queried in an online…

Machine Learning · Computer Science 2022-02-15 Aadirupa Saha , Pierre Gaillard

Exploration in reinforcement learning (RL) suffers from the curse of dimensionality when the state-action space is large. A common practice is to parameterize the high-dimensional value and policy functions using given features. However…

Machine Learning · Computer Science 2019-06-14 Lin F. Yang , Mengdi Wang

This paper investigates regret minimization, statistical inference, and their interplay in high-dimensional online decision-making based on the sparse linear context bandit model. We integrate the $\varepsilon$-greedy bandit algorithm for…

Machine Learning · Computer Science 2025-05-20 Congyuan Duan , Wanteng Ma , Jiashuo Jiang , Dong Xia

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 introduce the problem of model selection for contextual bandits, where a learner must adapt to the complexity of the optimal policy while balancing exploration and exploitation. Our main result is a new model selection guarantee for…

Machine Learning · Computer Science 2019-11-15 Dylan J. Foster , Akshay Krishnamurthy , Haipeng Luo

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 study linear contextual bandits under adversarial corruption and heavy-tailed noise with finite $(1+\epsilon)$-th moments for some $\epsilon \in (0,1]$. Existing work that addresses both adversarial corruption and heavy-tailed noise…

Machine Learning · Computer Science 2026-03-17 Naoto Tani , Futoshi Futami

We consider the problem of contextual bandits and imitation learning, where the learner lacks direct knowledge of the executed action's reward. Instead, the learner can actively query an expert at each round to compare two actions and…

Machine Learning · Computer Science 2023-07-25 Ayush Sekhari , Karthik Sridharan , Wen Sun , Runzhe Wu

We study high-probability regret bounds for adversarial $K$-armed bandits with time-varying feedback graphs over $T$ rounds. For general strongly observable graphs, we develop an algorithm that achieves the optimal regret…

Machine Learning · Computer Science 2023-01-31 Haipeng Luo , Hanghang Tong , Mengxiao Zhang , Yuheng Zhang

We study budget-constrained contextual bandits with adversarial contexts, where each action yields a random reward and incurs a random cost. We adopt the standard realizability assumption: conditioned on the observed context, rewards and…

Machine Learning · Computer Science 2026-05-08 Dhruv Sarkar , Abhishek Sinha

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

This study investigates the problem of $K$-armed linear contextual bandits, an instance of the multi-armed bandit problem, under an adversarial corruption. At each round, a decision-maker observes an independent and identically distributed…

Machine Learning · Computer Science 2023-12-29 Masahiro Kato , Shinji Ito

We present the first high-probability optimal regret bound for a policy optimization technique applied to the problem of stochastic contextual multi-armed bandit (CMAB) with general offline function approximation. Our algorithm is both…

Machine Learning · Computer Science 2026-02-17 Orin Levy , Yishay Mansour

In online learning, the data is provided in a sequential order, and the goal of the learner is to make online decisions to minimize overall regrets. This note is concerned with continuous-time models and algorithms for several online…

Machine Learning · Statistics 2024-05-20 Lexing Ying

This paper studies the adversarial graphical contextual bandits, a variant of adversarial multi-armed bandits that leverage two categories of the most common side information: \emph{contexts} and \emph{side observations}. In this setting, a…

Machine Learning · Computer Science 2021-02-18 Lingda Wang , Bingcong Li , Huozhi Zhou , Georgios B. Giannakis , Lav R. Varshney , Zhizhen Zhao

In this paper, we consider algorithm-independent lower bounds for the problem of black-box optimization of functions having a bounded norm is some Reproducing Kernel Hilbert Space (RKHS), which can be viewed as a non-Bayesian Gaussian…

Machine Learning · Statistics 2021-05-25 Xu Cai , Jonathan Scarlett