Faster Accelerated First-order Methods for Convex Optimization with Strongly Convex Function Constraints

Fuente: arXiv
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Autori principali: Lin, Zhenwei, Deng, Qi
Natura: Preprint
Pubblicazione: 2022
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author Lin, Zhenwei
Deng, Qi
author_facet Lin, Zhenwei
Deng, Qi
contents In this paper, we introduce faster accelerated primal-dual algorithms for minimizing a convex function subject to strongly convex function constraints. Prior to our work, the best complexity bound was $\mathcal{O}(1/{\varepsilon})$, regardless of the strong convexity of the constraint function. It is unclear whether the strong convexity assumption can enable even better convergence results. To address this issue, we have developed novel techniques to progressively estimate the strong convexity of the Lagrangian function. Our approach, for the first time, effectively leverages the constraint strong convexity, obtaining an improved complexity of $\mathcal{O}(1/\sqrt{\varepsilon})$. This rate matches the complexity lower bound for strongly-convex-concave saddle point optimization and is therefore order-optimal. We show the superior performance of our methods in sparsity-inducing constrained optimization, notably Google's personalized PageRank problem. Furthermore, we show that a restarted version of the proposed methods can effectively identify the optimal solution's sparsity pattern within a finite number of steps, a result that appears to have independent significance.
format Preprint
id arxiv_https___arxiv_org_abs_2212_11143
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Faster Accelerated First-order Methods for Convex Optimization with Strongly Convex Function Constraints
Lin, Zhenwei
Deng, Qi
Optimization and Control
Machine Learning
90C25, 90C30, 90C06
In this paper, we introduce faster accelerated primal-dual algorithms for minimizing a convex function subject to strongly convex function constraints. Prior to our work, the best complexity bound was $\mathcal{O}(1/{\varepsilon})$, regardless of the strong convexity of the constraint function. It is unclear whether the strong convexity assumption can enable even better convergence results. To address this issue, we have developed novel techniques to progressively estimate the strong convexity of the Lagrangian function. Our approach, for the first time, effectively leverages the constraint strong convexity, obtaining an improved complexity of $\mathcal{O}(1/\sqrt{\varepsilon})$. This rate matches the complexity lower bound for strongly-convex-concave saddle point optimization and is therefore order-optimal. We show the superior performance of our methods in sparsity-inducing constrained optimization, notably Google's personalized PageRank problem. Furthermore, we show that a restarted version of the proposed methods can effectively identify the optimal solution's sparsity pattern within a finite number of steps, a result that appears to have independent significance.
title Faster Accelerated First-order Methods for Convex Optimization with Strongly Convex Function Constraints
topic Optimization and Control
Machine Learning
90C25, 90C30, 90C06
url https://arxiv.org/abs/2212.11143