An Augmented Lagrangian Primal-Dual Semismooth Newton Method for Multi-Block Composite Optimization

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Deng, Zhanwang, Deng, Kangkang, Hu, Jiang, Wen, Zaiwen
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914797714407424
author Deng, Zhanwang
Deng, Kangkang
Hu, Jiang
Wen, Zaiwen
author_facet Deng, Zhanwang
Deng, Kangkang
Hu, Jiang
Wen, Zaiwen
contents In this paper, we develop a novel primal-dual semismooth Newton method for solving linearly constrained multi-block convex composite optimization problems. First, a differentiable augmented Lagrangian (AL) function is constructed by utilizing the Moreau envelopes of the nonsmooth functions. It enables us to derive an equivalent saddle point problem and establish the strong AL duality under the Slater's condition. Consequently, a semismooth system of nonlinear equations is formulated to characterize the optimality of the original problem instead of the inclusion-form KKT conditions. We then develop a semismooth Newton method, called ALPDSN, which uses purely second-order steps and a nonmonotone line search based globalization strategy. Through a connection to the inexact first-order steps when the regularization parameter is sufficiently large, the global convergence of ALPDSN is established. Under the regularity conditions, partial smoothness, the local error bound, and the strict complementarity, we show that both the primal and the dual iteration sequences possess a superlinear convergence rate and provide concrete examples where these regularity conditions are met. Numerical results on the image restoration with two regularization terms and the corrected tensor nuclear norm problem are presented to demonstrate the high efficiency and robustness of our ALPDSN.
format Preprint
id arxiv_https___arxiv_org_abs_2312_01273
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle An Augmented Lagrangian Primal-Dual Semismooth Newton Method for Multi-Block Composite Optimization
Deng, Zhanwang
Deng, Kangkang
Hu, Jiang
Wen, Zaiwen
Optimization and Control
In this paper, we develop a novel primal-dual semismooth Newton method for solving linearly constrained multi-block convex composite optimization problems. First, a differentiable augmented Lagrangian (AL) function is constructed by utilizing the Moreau envelopes of the nonsmooth functions. It enables us to derive an equivalent saddle point problem and establish the strong AL duality under the Slater's condition. Consequently, a semismooth system of nonlinear equations is formulated to characterize the optimality of the original problem instead of the inclusion-form KKT conditions. We then develop a semismooth Newton method, called ALPDSN, which uses purely second-order steps and a nonmonotone line search based globalization strategy. Through a connection to the inexact first-order steps when the regularization parameter is sufficiently large, the global convergence of ALPDSN is established. Under the regularity conditions, partial smoothness, the local error bound, and the strict complementarity, we show that both the primal and the dual iteration sequences possess a superlinear convergence rate and provide concrete examples where these regularity conditions are met. Numerical results on the image restoration with two regularization terms and the corrected tensor nuclear norm problem are presented to demonstrate the high efficiency and robustness of our ALPDSN.
title An Augmented Lagrangian Primal-Dual Semismooth Newton Method for Multi-Block Composite Optimization
topic Optimization and Control
url https://arxiv.org/abs/2312.01273