Separation of time scales in weakly interacting diffusions

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Adams, Zachary P., Engel, Maximilian, Gvalani, Rishabh S.
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866915158258876416
author Adams, Zachary P.
Engel, Maximilian
Gvalani, Rishabh S.
author_facet Adams, Zachary P.
Engel, Maximilian
Gvalani, Rishabh S.
contents We study metastable behaviour in systems of weakly interacting Brownian particles with localised, attractive potentials which are smooth and globally bounded. In this particular setting, numerical evidence suggests that the particles converge on a short time scale to a "droplet state" which is $metastable$, i.e. persists on a much longer time scale than the time scale of convergence, before eventually diffusing to $0$. In this article, we provide rigorous evidence and a quantitative characterisation of this separation of time scales. Working at the level of the empirical measure, we show that (after quotienting out the motion of the centre of mass) the rate of convergence to the quasi-stationary distribution, which corresponds with the droplet state, is $O(1)$ as the inverse temperature $β\to \infty$. Meanwhile the rate of leakage away from its centre of mass is $O(e^{-β})$. Futhermore, the quasi-stationary distribution is localised on a length scale of order $O(β^{-\frac12})$. We thus provide a partial answer to a question posed by Carrillo, Craig, and Yao (Aggregation-Diffusion Equations: Dynamics, Asymptotics, and Singular Limits. In: Active Particles, Volume 2, 2019) in the microscopic setting.
format Preprint
id arxiv_https___arxiv_org_abs_2502_12881
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Separation of time scales in weakly interacting diffusions
Adams, Zachary P.
Engel, Maximilian
Gvalani, Rishabh S.
Probability
Mathematical Physics
Analysis of PDEs
Dynamical Systems
Spectral Theory
We study metastable behaviour in systems of weakly interacting Brownian particles with localised, attractive potentials which are smooth and globally bounded. In this particular setting, numerical evidence suggests that the particles converge on a short time scale to a "droplet state" which is $metastable$, i.e. persists on a much longer time scale than the time scale of convergence, before eventually diffusing to $0$. In this article, we provide rigorous evidence and a quantitative characterisation of this separation of time scales. Working at the level of the empirical measure, we show that (after quotienting out the motion of the centre of mass) the rate of convergence to the quasi-stationary distribution, which corresponds with the droplet state, is $O(1)$ as the inverse temperature $β\to \infty$. Meanwhile the rate of leakage away from its centre of mass is $O(e^{-β})$. Futhermore, the quasi-stationary distribution is localised on a length scale of order $O(β^{-\frac12})$. We thus provide a partial answer to a question posed by Carrillo, Craig, and Yao (Aggregation-Diffusion Equations: Dynamics, Asymptotics, and Singular Limits. In: Active Particles, Volume 2, 2019) in the microscopic setting.
title Separation of time scales in weakly interacting diffusions
topic Probability
Mathematical Physics
Analysis of PDEs
Dynamical Systems
Spectral Theory
url https://arxiv.org/abs/2502.12881