A Gapped Scale-Sensitive Dimension and Lower Bounds for Offset Rademacher Complexity

Zeyu Jia, Yury Polyanskiy, Alexander Rakhlin

公開日: 2025/9/24

Abstract

We study gapped scale-sensitive dimensions of a function class in both sequential and non-sequential settings. We demonstrate that covering numbers for any uniformly bounded class are controlled above by these gapped dimensions, generalizing the results of \cite{anthony2000function,alon1997scale}. Moreover, we show that the gapped dimensions lead to lower bounds on offset Rademacher averages, thereby strengthening existing approaches for proving lower bounds on rates of convergence in statistical and online learning.