English

Multi-species Patlak-Keller-Segel system

Analysis of PDEs 2021-08-25 v3

Abstract

We study the regularity and large-time behavior of a crowd of species driven by chemo-tactic interactions. What distinguishes the different species is the way they interact with the rest of the crowd: the collective motion is driven by different chemical reactions which end up in a coupled system of parabolic Patlak-Keller-Segel equations. We show that the densities of the different species diffuse to zero provided the chemical interactions between the different species satisfy certain sub-critical condition; the latter is intimately related to a log-Hardy-Littlewood-Sobolev inequality for systems due to Shafrir & Wolansky. Thus for example, when two species interact, one of which has mass less than 4π4\pi, then the 2-system stays smooth for all time independent of the total mass of the system, in sharp contrast with the well-known breakdown of one specie with initial mass>8π> 8\pi.

Keywords

Cite

@article{arxiv.1903.02673,
  title  = {Multi-species Patlak-Keller-Segel system},
  author = {Siming He and Eitan Tadmor},
  journal= {arXiv preprint arXiv:1903.02673},
  year   = {2021}
}
R2 v1 2026-06-23T08:00:34.298Z