Learning smooth functions in high dimensions: from sparse polynomials to deep neural networks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Adcock, Ben, Brugiapaglia, Simone, Dexter, Nick, Moraga, Sebastian
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929303681236992
author Adcock, Ben
Brugiapaglia, Simone
Dexter, Nick
Moraga, Sebastian
author_facet Adcock, Ben
Brugiapaglia, Simone
Dexter, Nick
Moraga, Sebastian
contents Learning approximations to smooth target functions of many variables from finite sets of pointwise samples is an important task in scientific computing and its many applications in computational science and engineering. Despite well over half a century of research on high-dimensional approximation, this remains a challenging problem. Yet, significant advances have been made in the last decade towards efficient methods for doing this, commencing with so-called sparse polynomial approximation methods and continuing most recently with methods based on Deep Neural Networks (DNNs). In tandem, there have been substantial advances in the relevant approximation theory and analysis of these techniques. In this work, we survey this recent progress. We describe the contemporary motivations for this problem, which stem from parametric models and computational uncertainty quantification; the relevant function classes, namely, classes of infinite-dimensional, Banach-valued, holomorphic functions; fundamental limits of learnability from finite data for these classes; and finally, sparse polynomial and DNN methods for efficiently learning such functions from finite data. For the latter, there is currently a significant gap between the approximation theory of DNNs and the practical performance of deep learning. Aiming to narrow this gap, we develop the topic of practical existence theory, which asserts the existence of dimension-independent DNN architectures and training strategies that achieve provably near-optimal generalization errors in terms of the amount of training data.
format Preprint
id arxiv_https___arxiv_org_abs_2404_03761
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Learning smooth functions in high dimensions: from sparse polynomials to deep neural networks
Adcock, Ben
Brugiapaglia, Simone
Dexter, Nick
Moraga, Sebastian
Numerical Analysis
Machine Learning
Learning approximations to smooth target functions of many variables from finite sets of pointwise samples is an important task in scientific computing and its many applications in computational science and engineering. Despite well over half a century of research on high-dimensional approximation, this remains a challenging problem. Yet, significant advances have been made in the last decade towards efficient methods for doing this, commencing with so-called sparse polynomial approximation methods and continuing most recently with methods based on Deep Neural Networks (DNNs). In tandem, there have been substantial advances in the relevant approximation theory and analysis of these techniques. In this work, we survey this recent progress. We describe the contemporary motivations for this problem, which stem from parametric models and computational uncertainty quantification; the relevant function classes, namely, classes of infinite-dimensional, Banach-valued, holomorphic functions; fundamental limits of learnability from finite data for these classes; and finally, sparse polynomial and DNN methods for efficiently learning such functions from finite data. For the latter, there is currently a significant gap between the approximation theory of DNNs and the practical performance of deep learning. Aiming to narrow this gap, we develop the topic of practical existence theory, which asserts the existence of dimension-independent DNN architectures and training strategies that achieve provably near-optimal generalization errors in terms of the amount of training data.
title Learning smooth functions in high dimensions: from sparse polynomials to deep neural networks
topic Numerical Analysis
Machine Learning
url https://arxiv.org/abs/2404.03761