arXiv AI
Sep 24

Path Regularization: A Near-Complete and Optimal Nonasymptotic Generalization Theory for Multilayer Neural Networks and Double Descent Phenomenon

The paper presents a near-complete, nonasymptotic generalization theory for multilayer neural networks using path regularization, applicable to broad Lipschitz loss functions without requiring bounded loss or extreme network hyperparameters. It provides an explicit upper bound that addresses approximation rates in generalized Barron spaces and demonstrates the double descent phenomenon for ReLU networks. The authors claim near-minimax optimality for regression problems and plan to establish matching lower bounds in future work.

By Hao Yu
arXiv Machine Learning
Oct 9

Explaining the Saliency Map Sparsity of Adversarially-Trained Neural Networks

The paper investigates why saliency maps of adversarially‑trained neural networks appear sparse. It provides a theoretical explanation for two‑layer ReLU networks, showing that as data size and neuron count grow, minimizers converge to a Bayes classifier with minimal gradient and Barron norm. The sparsity arises because α−−‑training with λ−1 attacks yields anisotropic gradient norms that favor axis‑aligned, sparse gradients, a claim supported by experimental evaluation of gradient α‑norms and sparsity thresholds.

By Yannick Lunk, Atell Yehor Krasnopolsky, Damien Garreau, Leon Bungert