Spectral analysis for singularity formation of the two dimensional Keller-Segel system
Abstract
We analyse an operator arising in the description of singular solutions to the two-dimensional Keller-Segel problem. It corresponds to the linearised operator in parabolic self-similar variables, close to a concentrated stationary state. This is a two-scale problem, with a vanishing thin transition zone near the origin. Via rigorous matched asymptotic expansions, we describe the eigenvalues and eigenfunctions precisely. We also show a stability result with respect to suitable perturbations, as well as a coercivity estimate for the non-radial part. These results are used as key arguments in a new rigorous proof of the existence and refined description of singular solutions for the Keller-Segel problem by the authors. The present paper extends the result by Dejak, Lushnikov, Yu, Ovchinnikov and Sigal [Physica D, 2012]. Two major difficulties arise in the analysis: this is a singular limit problem, and a degeneracy causes corrections not being polynomial but logarithmic with respect to the main parameter.
Keywords
Cite
@article{arxiv.1911.10884,
title = {Spectral analysis for singularity formation of the two dimensional Keller-Segel system},
author = {Charles Collot and Tej-Eddine Ghoul and Nader Masmoudi and Van Tien Nguyen},
journal= {arXiv preprint arXiv:1911.10884},
year = {2020}
}
Comments
48 pages. Improved the presentation and the readability of the paper