What kinds of functions do deep neural networks learn? Insights from variational spline theory

R Parhi, RD Nowak - SIAM Journal on Mathematics of Data Science, 2022 - SIAM
We develop a variational framework to understand the properties of functions learned by
fitting deep neural networks with rectified linear unit (ReLU) activations to data. We propose …

[HTML][HTML] Deep networks for system identification: a survey

G Pillonetto, A Aravkin, D Gedon, L Ljung, AH Ribeiro… - Automatica, 2025 - Elsevier
Deep learning is a topic of considerable current interest. The availability of massive data
collections and powerful software resources has led to an impressive amount of results in …

Deep learning meets sparse regularization: A signal processing perspective

R Parhi, RD Nowak - IEEE Signal Processing Magazine, 2023 - ieeexplore.ieee.org
Deep learning (DL) has been wildly successful in practice, and most of the state-of-the-art
machine learning methods are based on neural networks (NNs). Lacking, however, is a …

Optimal Rates of Approximation by Shallow ReLU Neural Networks and Applications to Nonparametric Regression

Y Yang, DX Zhou - Constructive Approximation, 2024 - Springer
We study the approximation capacity of some variation spaces corresponding to shallow
ReLU k neural networks. It is shown that sufficiently smooth functions are contained in these …

Linear neural network layers promote learning single-and multiple-index models

S Parkinson, G Ongie, R Willett - arXiv preprint arXiv:2305.15598, 2023 - arxiv.org
This paper explores the implicit bias of overparameterized neural networks of depth greater
than two layers. Our framework considers a family of networks of varying depths that all have …

Deep Learning meets Nonparametric Regression: Are Weight-Decayed DNNs Locally Adaptive?

K Zhang, YX Wang - arXiv preprint arXiv:2204.09664, 2022 - arxiv.org
We study the theory of neural network (NN) from the lens of classical nonparametric
regression problems with a focus on NN's ability to adaptively estimate functions with …

Variation spaces for multi-output neural networks: Insights on multi-task learning and network compression

J Shenouda, R Parhi, K Lee, RD Nowak - Journal of Machine Learning …, 2024 - jmlr.org
This paper introduces a novel theoretical framework for the analysis of vector-valued neural
networks through the development of vector-valued variation spaces, a new class of …

A Regularity Theory for Static Schrödinger Equations on d in Spectral Barron Spaces

Z Chen, J Lu, Y Lu, S Zhou - SIAM Journal on Mathematical Analysis, 2023 - SIAM
Spectral Barron spaces have received considerable interest recently, as it is the natural
function space for approximation theory of two-layer neural networks with a dimension-free …

[PDF][PDF] Nonparametric regression using over-parameterized shallow ReLU neural networks

Y Yang, DX Zhou - Journal of Machine Learning Research, 2024 - jmlr.org
It is shown that over-parameterized neural networks can achieve minimax optimal rates of
convergence (up to logarithmic factors) for learning functions from certain smooth function …

Distributional Extension and Invertibility of the -Plane Transform and Its Dual

R Parhi, M Unser - SIAM Journal on Mathematical Analysis, 2024 - SIAM
We investigate the distributional extension of the-plane transform in and of related operators.
We parameterize the-plane domain as the Cartesian product of the Stiefel manifold of …