Connection between a degenerate particle flow model and a free boundary problem

Fuente: arXiv
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Main Authors: Chen, Li, Göttlich, Simone, Zamponi, Nicola
Format: Preprint
Published: 2022
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author Chen, Li
Göttlich, Simone
Zamponi, Nicola
author_facet Chen, Li
Göttlich, Simone
Zamponi, Nicola
contents In this paper a strongly degenerate parabolic equation derived from a density dependent particle flow model is studied. Furthermore, a free boundary problem and its connection to the strongly degenerate parabolic equation is investigated. First, it is shown that the strongly degenerate parabolic equation has a unique global bounded weak solution that converges towards a steady state for large time horizons. Two scenarios might occur: When the average density $ρ_{\infty}$ is larger than a certain critical density $ρ_{cr}$, the steady state coincides with $ρ_{\infty}$ and the convergence rate is exponential in the $L^2$ norm; while in the opposite case $ρ_{\infty}<ρ_{cr}$, the steady state is unknown and the convergence is algebraic in a negative Sobolev seminorm. Further investigations show that for radially symmetric and decreasing initial data, the solution of the strongly degenerate parabolic equation can be constructed by using the solution of a corresponding free boundary problem. Moreover, the global existence of weak solutions to the latter problem is proved. Finally, numerical experiments in two space dimensions are presented, which show that segregation phenomena can appear when the initial average density is smaller than the critical density.
format Preprint
id arxiv_https___arxiv_org_abs_2202_04416
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Connection between a degenerate particle flow model and a free boundary problem
Chen, Li
Göttlich, Simone
Zamponi, Nicola
Analysis of PDEs
35K65, 35R35, 65M06
In this paper a strongly degenerate parabolic equation derived from a density dependent particle flow model is studied. Furthermore, a free boundary problem and its connection to the strongly degenerate parabolic equation is investigated. First, it is shown that the strongly degenerate parabolic equation has a unique global bounded weak solution that converges towards a steady state for large time horizons. Two scenarios might occur: When the average density $ρ_{\infty}$ is larger than a certain critical density $ρ_{cr}$, the steady state coincides with $ρ_{\infty}$ and the convergence rate is exponential in the $L^2$ norm; while in the opposite case $ρ_{\infty}<ρ_{cr}$, the steady state is unknown and the convergence is algebraic in a negative Sobolev seminorm. Further investigations show that for radially symmetric and decreasing initial data, the solution of the strongly degenerate parabolic equation can be constructed by using the solution of a corresponding free boundary problem. Moreover, the global existence of weak solutions to the latter problem is proved. Finally, numerical experiments in two space dimensions are presented, which show that segregation phenomena can appear when the initial average density is smaller than the critical density.
title Connection between a degenerate particle flow model and a free boundary problem
topic Analysis of PDEs
35K65, 35R35, 65M06
url https://arxiv.org/abs/2202.04416