Polarized consensus-based dynamics for optimization and sampling

Fuente: arXiv
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Autori principali: Bungert, Leon, Roith, Tim, Wacker, Philipp
Natura: Preprint
Pubblicazione: 2022
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author Bungert, Leon
Roith, Tim
Wacker, Philipp
author_facet Bungert, Leon
Roith, Tim
Wacker, Philipp
contents In this paper we propose polarized consensus-based dynamics in order to make consensus-based optimization (CBO) and sampling (CBS) applicable for objective functions with several global minima or distributions with many modes, respectively. For this, we ``polarize'' the dynamics with a localizing kernel and the resulting model can be viewed as a bounded confidence model for opinion formation in the presence of common objective. Instead of being attracted to a common weighted mean as in the original consensus-based methods, which prevents the detection of more than one minimum or mode, in our method every particle is attracted to a weighted mean which gives more weight to nearby particles. We prove that in the mean-field regime the polarized CBS dynamics are unbiased for Gaussian targets. We also prove that in the zero temperature limit and for sufficiently well-behaved strongly convex objectives the solution of the Fokker--Planck equation converges in the Wasserstein-2 distance to a Dirac measure at the minimizer. Finally, we propose a computationally more efficient generalization which works with a predefined number of clusters and improves upon our polarized baseline method for high-dimensional optimization.
format Preprint
id arxiv_https___arxiv_org_abs_2211_05238
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Polarized consensus-based dynamics for optimization and sampling
Bungert, Leon
Roith, Tim
Wacker, Philipp
Optimization and Control
Numerical Analysis
90C26, 35Q93, 35B40, 65N21
In this paper we propose polarized consensus-based dynamics in order to make consensus-based optimization (CBO) and sampling (CBS) applicable for objective functions with several global minima or distributions with many modes, respectively. For this, we ``polarize'' the dynamics with a localizing kernel and the resulting model can be viewed as a bounded confidence model for opinion formation in the presence of common objective. Instead of being attracted to a common weighted mean as in the original consensus-based methods, which prevents the detection of more than one minimum or mode, in our method every particle is attracted to a weighted mean which gives more weight to nearby particles. We prove that in the mean-field regime the polarized CBS dynamics are unbiased for Gaussian targets. We also prove that in the zero temperature limit and for sufficiently well-behaved strongly convex objectives the solution of the Fokker--Planck equation converges in the Wasserstein-2 distance to a Dirac measure at the minimizer. Finally, we propose a computationally more efficient generalization which works with a predefined number of clusters and improves upon our polarized baseline method for high-dimensional optimization.
title Polarized consensus-based dynamics for optimization and sampling
topic Optimization and Control
Numerical Analysis
90C26, 35Q93, 35B40, 65N21
url https://arxiv.org/abs/2211.05238