EUROPT 2025
Abstract Submission

44. Monotone and nonmonotone linearized block coordinate descent methods for nonsmooth composite optimization problems

Invited abstract in session TB-6: Advances in nonsmooth optimization, stream Nonsmooth and nonconvex optimization.

Tuesday, 10:30-12:30
Room: B100/7013

Authors (first author is the speaker)

1. Yassine Nabou
Department of Mathematics and Statistics, University of Helsinki
2. Lahcen EL BOURKHISSI
Department of Automatic Control and Systems Engineering, University POLITEHNICA of Bucharest
3. Sebastian Stich
CISPA Helmholtz Center for Information Security
4. Tuomo Valkonen
Escuela Politécnica Nacional

Abstract

In this paper, we introduce both monotone and nonmonotone variants of LiBCoD, a Linearized Block Coordinate Descent method for solving composite optimization problems. At each iteration, a random block is selected, and the smooth components of the objective are linearized along the chosen block in a Gauss-Newton approach. For the monotone variant, we establish a global sublinear convergence rate to a stationary point under the assumption of bounded iterates. For the nonmonotone variant, we derive a global sublinear convergence rate without requiring global Lipschitz continuity or bounded iterates. Preliminary numerical experiments on logistic regression highlight the promising performance of the proposed approach.

Keywords

Status: accepted


Back to the list of papers