EUROPT 2025
Abstract Submission

354. Learning from data via overparameterization

Invited abstract in session MD-10: Interactions between optimization and machine learning, stream Zeroth and first-order optimization methods.

Monday, 16:30-18:30
Room: B100/8011

Authors (first author is the speaker)

1. Cesare Molinari
Università di Genova
2. Silvia Villa
Department of Mathematics, MaLGa, università di Genova
3. Lorenzo Rosasco
MaLGa, DIBRIS, Università di Genova
4. Cristian Vega
Dima, University of Genoa
5. Hippolyte Labarrière
Università di Genova

Abstract

Solving data driven problems requires defining complex models and fitting them on data, neural networks being a motivating example. The fitting procedure can be seen as an optimization problem which is often non convex, and hence optimization guarantees hard to derive. An opportunity is provided by viewing the model of interest as a redundant re-parameterization - an overparametrization - of some simpler model for which optimization results are easier to achieve. In this talk, after formalizing the above idea, we review some recent results and derive new ones. In particular, we consider the gradient flow of some classes of linear overparamtetrization and show they correspond to suitable mirror flow on the original parameters. Our main contribution relates to the study of the latter, for which we establish well posed-ness and convergence. The results yields insight on the role of overparametrization for implicit regularization and constrained optimization.

Keywords

Status: accepted


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