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Hypothesis Spaces for Deep Learning

Machine Learning 2025-08-15 v3 Machine Learning Functional Analysis

Abstract

This paper introduces a hypothesis space for deep learning based on deep neural networks (DNNs). By treating a DNN as a function of two variables - the input variable and the parameter variable - we consider the set of DNNs where the parameter variable belongs to a space of weight matrices and biases determined by a prescribed depth and layer widths. To construct a Banach space of functions of the input variable, we take the weak* closure of the linear span of this DNN set. We prove that the resulting Banach space is a reproducing kernel Banach space (RKBS) and explicitly construct its reproducing kernel. Furthermore, we investigate two learning models - regularized learning and the minimum norm interpolation (MNI) problem - within the RKBS framework by establishing representer theorems. These theorems reveal that the solutions to these learning problems can be expressed as a finite sum of kernel expansions based on training data.

Keywords

Cite

@article{arxiv.2403.03353,
  title  = {Hypothesis Spaces for Deep Learning},
  author = {Rui Wang and Yuesheng Xu and Mingsong Yan},
  journal= {arXiv preprint arXiv:2403.03353},
  year   = {2025}
}
R2 v1 2026-06-28T15:10:25.957Z