A quasi-stationary approach to the long-term asymptotics of the growth-fragmentation equation

Fuente: arXiv
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Main Authors: Villemonais, Denis, Watson, Alexander
Format: Preprint
Published: 2022
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author Villemonais, Denis
Watson, Alexander
author_facet Villemonais, Denis
Watson, Alexander
contents In a growth-fragmentation system, cells grow in size slowly and split apart at random. Typically, the number of cells in the system grows exponentially and the distribution of the sizes of cells settles into an equilibrium 'asymptotic profile'. In this work we introduce a new method to prove this asymptotic behaviour for the growth-fragmentation equation, and show that the convergence to the asymptotic profile occurs at exponential rate. We do this by identifying an associated sub-Markov process and studying its quasi-stationary behaviour via a Lyapunov function condition. By doing so, we are able to simplify and generalise results in a number of common cases and offer a unified framework for their study. In the course of this work we are also able to prove the existence and uniqueness of solutions to the growth-fragmentation equation in a wide range of situations.
format Preprint
id arxiv_https___arxiv_org_abs_2202_12553
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle A quasi-stationary approach to the long-term asymptotics of the growth-fragmentation equation
Villemonais, Denis
Watson, Alexander
Probability
In a growth-fragmentation system, cells grow in size slowly and split apart at random. Typically, the number of cells in the system grows exponentially and the distribution of the sizes of cells settles into an equilibrium 'asymptotic profile'. In this work we introduce a new method to prove this asymptotic behaviour for the growth-fragmentation equation, and show that the convergence to the asymptotic profile occurs at exponential rate. We do this by identifying an associated sub-Markov process and studying its quasi-stationary behaviour via a Lyapunov function condition. By doing so, we are able to simplify and generalise results in a number of common cases and offer a unified framework for their study. In the course of this work we are also able to prove the existence and uniqueness of solutions to the growth-fragmentation equation in a wide range of situations.
title A quasi-stationary approach to the long-term asymptotics of the growth-fragmentation equation
topic Probability
url https://arxiv.org/abs/2202.12553