English

Geometry of Critical Sets and Existence of Saddle Branches for Two-layer Neural Networks

Machine Learning 2024-05-29 v1 Optimization and Control

Abstract

This paper presents a comprehensive analysis of critical point sets in two-layer neural networks. To study such complex entities, we introduce the critical embedding operator and critical reduction operator as our tools. Given a critical point, we use these operators to uncover the whole underlying critical set representing the same output function, which exhibits a hierarchical structure. Furthermore, we prove existence of saddle branches for any critical set whose output function can be represented by a narrower network. Our results provide a solid foundation to the further study of optimization and training behavior of neural networks.

Keywords

Cite

@article{arxiv.2405.17501,
  title  = {Geometry of Critical Sets and Existence of Saddle Branches for Two-layer Neural Networks},
  author = {Leyang Zhang and Yaoyu Zhang and Tao Luo},
  journal= {arXiv preprint arXiv:2405.17501},
  year   = {2024}
}