Adaptive Newton-CG methods with global and local analysis for unconstrained optimization with Hölder continuous Hessian

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Zeng, Ziyang, Zhang, Junyu, He, Chuan
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909000497364992
author Zeng, Ziyang
Zhang, Junyu
He, Chuan
author_facet Zeng, Ziyang
Zhang, Junyu
He, Chuan
contents In this paper, we study Newton-conjugate gradient (Newton-CG) methods for minimizing a nonconvex function $f$ whose Hessian is $(H_f,ν)$-Hölder continuous with modulus $H_f>0$ and exponent $ν\in(0,1]$. Recently proposed Newton-CG methods for this problem adopt (i) non-adaptive regularization and (ii) a nested line-search procedure, where (i) often leads to inefficient early progress and the loss of local superlinear convergence, and (ii) may incur high computational cost due to multiple solves of the Newton system per iteration. To address these limitations, we propose two novel Newton-CG algorithms, depending on the availability of $ν$, that adaptively regularize the Newton system by leveraging the auto-conditioning technique to eliminate the nested line search. The proposed algorithms achieve the best-known iteration complexity ${\mathcal O}\big(H_f^{1/(1+ν)}ε^{-(2+ν)/(1+ν)}\big)$ for finding an $ε$-stationary point and, simultaneously, enjoy local superlinear convergence near nondegenerate local minimizers. Numerical experiments further demonstrate the practical advantages of our algorithms over existing approaches.
format Preprint
id arxiv_https___arxiv_org_abs_2604_02763
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Adaptive Newton-CG methods with global and local analysis for unconstrained optimization with Hölder continuous Hessian
Zeng, Ziyang
Zhang, Junyu
He, Chuan
Optimization and Control
In this paper, we study Newton-conjugate gradient (Newton-CG) methods for minimizing a nonconvex function $f$ whose Hessian is $(H_f,ν)$-Hölder continuous with modulus $H_f>0$ and exponent $ν\in(0,1]$. Recently proposed Newton-CG methods for this problem adopt (i) non-adaptive regularization and (ii) a nested line-search procedure, where (i) often leads to inefficient early progress and the loss of local superlinear convergence, and (ii) may incur high computational cost due to multiple solves of the Newton system per iteration. To address these limitations, we propose two novel Newton-CG algorithms, depending on the availability of $ν$, that adaptively regularize the Newton system by leveraging the auto-conditioning technique to eliminate the nested line search. The proposed algorithms achieve the best-known iteration complexity ${\mathcal O}\big(H_f^{1/(1+ν)}ε^{-(2+ν)/(1+ν)}\big)$ for finding an $ε$-stationary point and, simultaneously, enjoy local superlinear convergence near nondegenerate local minimizers. Numerical experiments further demonstrate the practical advantages of our algorithms over existing approaches.
title Adaptive Newton-CG methods with global and local analysis for unconstrained optimization with Hölder continuous Hessian
topic Optimization and Control
url https://arxiv.org/abs/2604.02763