Score-based generative models break the curse of dimensionality in learning a family of sub-Gaussian probability distributions

Fuente: arXiv
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Autores principales: Cole, Frank, Lu, Yulong
Formato: Preprint
Publicado: 2024
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author Cole, Frank
Lu, Yulong
author_facet Cole, Frank
Lu, Yulong
contents While score-based generative models (SGMs) have achieved remarkable success in enormous image generation tasks, their mathematical foundations are still limited. In this paper, we analyze the approximation and generalization of SGMs in learning a family of sub-Gaussian probability distributions. We introduce a notion of complexity for probability distributions in terms of their relative density with respect to the standard Gaussian measure. We prove that if the log-relative density can be locally approximated by a neural network whose parameters can be suitably bounded, then the distribution generated by empirical score matching approximates the target distribution in total variation with a dimension-independent rate. We illustrate our theory through examples, which include certain mixtures of Gaussians. An essential ingredient of our proof is to derive a dimension-free deep neural network approximation rate for the true score function associated with the forward process, which is interesting in its own right.
format Preprint
id arxiv_https___arxiv_org_abs_2402_08082
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Score-based generative models break the curse of dimensionality in learning a family of sub-Gaussian probability distributions
Cole, Frank
Lu, Yulong
Machine Learning
While score-based generative models (SGMs) have achieved remarkable success in enormous image generation tasks, their mathematical foundations are still limited. In this paper, we analyze the approximation and generalization of SGMs in learning a family of sub-Gaussian probability distributions. We introduce a notion of complexity for probability distributions in terms of their relative density with respect to the standard Gaussian measure. We prove that if the log-relative density can be locally approximated by a neural network whose parameters can be suitably bounded, then the distribution generated by empirical score matching approximates the target distribution in total variation with a dimension-independent rate. We illustrate our theory through examples, which include certain mixtures of Gaussians. An essential ingredient of our proof is to derive a dimension-free deep neural network approximation rate for the true score function associated with the forward process, which is interesting in its own right.
title Score-based generative models break the curse of dimensionality in learning a family of sub-Gaussian probability distributions
topic Machine Learning
url https://arxiv.org/abs/2402.08082