Underdamped Diffusion Bridges with Applications to Sampling

Fuente: arXiv
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Auteurs principaux: Blessing, Denis, Berner, Julius, Richter, Lorenz, Neumann, Gerhard
Format: Preprint
Publié: 2025
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author Blessing, Denis
Berner, Julius
Richter, Lorenz
Neumann, Gerhard
author_facet Blessing, Denis
Berner, Julius
Richter, Lorenz
Neumann, Gerhard
contents We provide a general framework for learning diffusion bridges that transport prior to target distributions. It includes existing diffusion models for generative modeling, but also underdamped versions with degenerate diffusion matrices, where the noise only acts in certain dimensions. Extending previous findings, our framework allows to rigorously show that score matching in the underdamped case is indeed equivalent to maximizing a lower bound on the likelihood. Motivated by superior convergence properties and compatibility with sophisticated numerical integration schemes of underdamped stochastic processes, we propose \emph{underdamped diffusion bridges}, where a general density evolution is learned rather than prescribed by a fixed noising process. We apply our method to the challenging task of sampling from unnormalized densities without access to samples from the target distribution. Across a diverse range of sampling problems, our approach demonstrates state-of-the-art performance, notably outperforming alternative methods, while requiring significantly fewer discretization steps and no hyperparameter tuning.
format Preprint
id arxiv_https___arxiv_org_abs_2503_01006
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Underdamped Diffusion Bridges with Applications to Sampling
Blessing, Denis
Berner, Julius
Richter, Lorenz
Neumann, Gerhard
Machine Learning
We provide a general framework for learning diffusion bridges that transport prior to target distributions. It includes existing diffusion models for generative modeling, but also underdamped versions with degenerate diffusion matrices, where the noise only acts in certain dimensions. Extending previous findings, our framework allows to rigorously show that score matching in the underdamped case is indeed equivalent to maximizing a lower bound on the likelihood. Motivated by superior convergence properties and compatibility with sophisticated numerical integration schemes of underdamped stochastic processes, we propose \emph{underdamped diffusion bridges}, where a general density evolution is learned rather than prescribed by a fixed noising process. We apply our method to the challenging task of sampling from unnormalized densities without access to samples from the target distribution. Across a diverse range of sampling problems, our approach demonstrates state-of-the-art performance, notably outperforming alternative methods, while requiring significantly fewer discretization steps and no hyperparameter tuning.
title Underdamped Diffusion Bridges with Applications to Sampling
topic Machine Learning
url https://arxiv.org/abs/2503.01006