Sampling metastable systems using collective variables and Jarzynski-Crooks paths

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Schönle, Christoph, Gabrié, Marylou, Lelièvre, Tony, Stoltz, Gabriel
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916599302193152
author Schönle, Christoph
Gabrié, Marylou
Lelièvre, Tony
Stoltz, Gabriel
author_facet Schönle, Christoph
Gabrié, Marylou
Lelièvre, Tony
Stoltz, Gabriel
contents We consider the problem of sampling a high dimensional multimodal target probability measure. We assume that a good proposal kernel to move only a subset of the degrees of freedoms (also known as collective variables) is known a priori. This proposal kernel can for example be built using normalizing flows. We show how to extend the move from the collective variable space to the full space and how to implement an accept-reject step in order to get a reversible chain with respect to a target probability measure. The accept-reject step does not require to know the marginal of the original measure in the collective variable (namely to know the free energy). The obtained algorithm admits several variants, some of them being very close to methods which have been proposed previously in the literature. We show how the obtained acceptance ratio can be expressed in terms of the work which appears in the Jarzynski-Crooks equality, at least for some variants. Numerical illustrations demonstrate the efficiency of the approach on various simple test cases, and allow us to compare the variants of the algorithm.
format Preprint
id arxiv_https___arxiv_org_abs_2405_18160
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Sampling metastable systems using collective variables and Jarzynski-Crooks paths
Schönle, Christoph
Gabrié, Marylou
Lelièvre, Tony
Stoltz, Gabriel
Statistical Mechanics
Computation
We consider the problem of sampling a high dimensional multimodal target probability measure. We assume that a good proposal kernel to move only a subset of the degrees of freedoms (also known as collective variables) is known a priori. This proposal kernel can for example be built using normalizing flows. We show how to extend the move from the collective variable space to the full space and how to implement an accept-reject step in order to get a reversible chain with respect to a target probability measure. The accept-reject step does not require to know the marginal of the original measure in the collective variable (namely to know the free energy). The obtained algorithm admits several variants, some of them being very close to methods which have been proposed previously in the literature. We show how the obtained acceptance ratio can be expressed in terms of the work which appears in the Jarzynski-Crooks equality, at least for some variants. Numerical illustrations demonstrate the efficiency of the approach on various simple test cases, and allow us to compare the variants of the algorithm.
title Sampling metastable systems using collective variables and Jarzynski-Crooks paths
topic Statistical Mechanics
Computation
url https://arxiv.org/abs/2405.18160