Implicit Regularisation in Diffusion Models: An Algorithm-Dependent Generalisation Analysis

Fuente: arXiv
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Main Authors: Farghly, Tyler, Rebeschini, Patrick, Deligiannidis, George, Doucet, Arnaud
Format: Preprint
Published: 2025
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author Farghly, Tyler
Rebeschini, Patrick
Deligiannidis, George
Doucet, Arnaud
author_facet Farghly, Tyler
Rebeschini, Patrick
Deligiannidis, George
Doucet, Arnaud
contents The success of denoising diffusion models raises important questions regarding their generalisation behaviour, particularly in high-dimensional settings. Notably, it has been shown that when training and sampling are performed perfectly, these models memorise training data -- implying that some form of regularisation is essential for generalisation. Existing theoretical analyses primarily rely on algorithm-independent techniques such as uniform convergence, heavily utilising model structure to obtain generalisation bounds. In this work, we instead leverage the algorithmic aspects that promote generalisation in diffusion models, developing a general theory of algorithm-dependent generalisation for this setting. Borrowing from the framework of algorithmic stability, we introduce the notion of score stability, which quantifies the sensitivity of score-matching algorithms to dataset perturbations. We derive generalisation bounds in terms of score stability, and apply our framework to several fundamental learning settings, identifying sources of regularisation. In particular, we consider denoising score matching with early stopping (denoising regularisation), sampler-wide coarse discretisation (sampler regularisation) and optimising with SGD (optimisation regularisation). By grounding our analysis in algorithmic properties rather than model structure, we identify multiple sources of implicit regularisation unique to diffusion models that have so far been overlooked in the literature.
format Preprint
id arxiv_https___arxiv_org_abs_2507_03756
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Implicit Regularisation in Diffusion Models: An Algorithm-Dependent Generalisation Analysis
Farghly, Tyler
Rebeschini, Patrick
Deligiannidis, George
Doucet, Arnaud
Machine Learning
Statistics Theory
The success of denoising diffusion models raises important questions regarding their generalisation behaviour, particularly in high-dimensional settings. Notably, it has been shown that when training and sampling are performed perfectly, these models memorise training data -- implying that some form of regularisation is essential for generalisation. Existing theoretical analyses primarily rely on algorithm-independent techniques such as uniform convergence, heavily utilising model structure to obtain generalisation bounds. In this work, we instead leverage the algorithmic aspects that promote generalisation in diffusion models, developing a general theory of algorithm-dependent generalisation for this setting. Borrowing from the framework of algorithmic stability, we introduce the notion of score stability, which quantifies the sensitivity of score-matching algorithms to dataset perturbations. We derive generalisation bounds in terms of score stability, and apply our framework to several fundamental learning settings, identifying sources of regularisation. In particular, we consider denoising score matching with early stopping (denoising regularisation), sampler-wide coarse discretisation (sampler regularisation) and optimising with SGD (optimisation regularisation). By grounding our analysis in algorithmic properties rather than model structure, we identify multiple sources of implicit regularisation unique to diffusion models that have so far been overlooked in the literature.
title Implicit Regularisation in Diffusion Models: An Algorithm-Dependent Generalisation Analysis
topic Machine Learning
Statistics Theory
url https://arxiv.org/abs/2507.03756