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arXiv 1310.7771math.AP
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Keller-Segel方程的唯一性和长时间渐近性:抛物-椭圆情形

Uniqueness and long time asymptotic for the Keller-Segel equation: The parabolic-elliptic case

Fernandez Giani Egana, Stéphane Mischler

摘要:

本文在弱解(或“自由能”解)的一般框架下研究了具有有限质量$M$、有限二阶矩和有限熵的抛物椭圆型Keller-Segel方程.本文的目的有三:(1)证明了当$M\le8π$和$T^*< \infty$满足$M\le8π$和$M> 8π$满足$T^*< \infty$时,$[0,T^*)$和$T^*=\infty$在最大存在区间上的“自由能”解的唯一性.证明使用DiPerna-Lions重整化参数,这使得有可能得到“最佳正则性”以及在临界$L^{4/3}$ Lebesgue范数下两个可能解的差的估计,类似于$2d$涡度Navier-Stokes方程。(2)我们证明了即时平滑效果,并在$M < 8π$的情况下,我们证明了索伯列夫范数界统一的时间尺度的解决方案(对应于自相似变量)。(3)在$M < 8π$的情况下,我们还证明了加权$L^{4/3}$线性化的自相似轮廓的稳定性,然后普遍的最佳收敛速率的解决方案的自相似轮廓。证明主要是基于半群谱隙的泛函空间的扩大的论证。

英文摘要:

The present paper deals with the parabolic-elliptic Keller-Segel equation in the plane in the general framework of weak (or ''free energy") solutions associated to initial datum with finite mass $M$, finite second moment and finite entropy. The aim of the paper is threefold: (1) We prove the uniqueness of the ''free energy" solution on the maximal interval of existence $[0,T^*)$ with $T^*=\infty$ in the case when $M\le8π$ and $T^*< \infty$ in the case when $M> 8π$. The proof uses a DiPerna-Lions renormalizing argument which makes possible to get the ''optimal regularity" as well as an estimate of the difference of two possible solutions in the critical $L^{4/3}$ Lebesgue norm similarly as for the $2d$ vorticity Navier-Stokes equation. (2) We prove immediate smoothing effect and, in the case $M < 8π$, we prove Sobolev norm bound uniformly in time for the rescaled solution (corresponding to the self-similar variables). (3) In the case $M < 8π$, we also prove weighted $L^{4/3}$ linearized stability of the self-similar profile and then universal optimal rate of convergence of the solution to the self-similar profile. The proof is mainly based on an argument of enlargement of the functional space for semigroup spectral gap.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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