Exploiting Curvature in Online Convex Optimization with Delayed Feedback

Fuente: arXiv
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Main Authors: Qiu, Hao, Esposito, Emmanuel, Zhang, Mengxiao
Format: Preprint
Published: 2025
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author Qiu, Hao
Esposito, Emmanuel
Zhang, Mengxiao
author_facet Qiu, Hao
Esposito, Emmanuel
Zhang, Mengxiao
contents In this work, we study the online convex optimization problem with curved losses and delayed feedback. When losses are strongly convex, existing approaches obtain regret bounds of order $d_{\max} \ln T$, where $d_{\max}$ is the maximum delay and $T$ is the time horizon. However, in many cases, this guarantee can be much worse than $\sqrt{d_{\mathrm{tot}}}$ as obtained by a delayed version of online gradient descent, where $d_{\mathrm{tot}}$ is the total delay. We bridge this gap by proposing a variant of follow-the-regularized-leader that obtains regret of order $\min\{σ_{\max}\ln T, \sqrt{d_{\mathrm{tot}}}\}$, where $σ_{\max}$ is the maximum number of missing observations. We then consider exp-concave losses and extend the Online Newton Step algorithm to handle delays with an adaptive learning rate tuning, achieving regret $\min\{d_{\max} n\ln T, \sqrt{d_{\mathrm{tot}}}\}$ where $n$ is the dimension. To our knowledge, this is the first algorithm to achieve such a regret bound for exp-concave losses. We further consider the problem of unconstrained online linear regression and achieve a similar guarantee by designing a variant of the Vovk-Azoury-Warmuth forecaster with a clipping trick. Finally, we implement our algorithms and conduct experiments under various types of delay and losses, showing an improved performance over existing methods.
format Preprint
id arxiv_https___arxiv_org_abs_2506_07595
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Exploiting Curvature in Online Convex Optimization with Delayed Feedback
Qiu, Hao
Esposito, Emmanuel
Zhang, Mengxiao
Machine Learning
In this work, we study the online convex optimization problem with curved losses and delayed feedback. When losses are strongly convex, existing approaches obtain regret bounds of order $d_{\max} \ln T$, where $d_{\max}$ is the maximum delay and $T$ is the time horizon. However, in many cases, this guarantee can be much worse than $\sqrt{d_{\mathrm{tot}}}$ as obtained by a delayed version of online gradient descent, where $d_{\mathrm{tot}}$ is the total delay. We bridge this gap by proposing a variant of follow-the-regularized-leader that obtains regret of order $\min\{σ_{\max}\ln T, \sqrt{d_{\mathrm{tot}}}\}$, where $σ_{\max}$ is the maximum number of missing observations. We then consider exp-concave losses and extend the Online Newton Step algorithm to handle delays with an adaptive learning rate tuning, achieving regret $\min\{d_{\max} n\ln T, \sqrt{d_{\mathrm{tot}}}\}$ where $n$ is the dimension. To our knowledge, this is the first algorithm to achieve such a regret bound for exp-concave losses. We further consider the problem of unconstrained online linear regression and achieve a similar guarantee by designing a variant of the Vovk-Azoury-Warmuth forecaster with a clipping trick. Finally, we implement our algorithms and conduct experiments under various types of delay and losses, showing an improved performance over existing methods.
title Exploiting Curvature in Online Convex Optimization with Delayed Feedback
topic Machine Learning
url https://arxiv.org/abs/2506.07595