报告人简介：Michael Winkler教授的研究方向为偏微分方程的定性分析，现为德国帕德博恩大学偏微分方程研究方向的学术带头人，也是国际趋化模型研究领域的学术带头人之一，目前担任5份SCI国际期刊编委。Michael Winkler教授发表期刊论文140余篇，据Mathematical Reviews数据库记录，被引用约4000次，连续3年入选科睿唯安“全球高被引科学家”。

内容摘要：This talk addresses a parabolic-elliptic Keller-Segel systemwith homogeneous Neumann boundary conditions in the ball. The main objective is to reveal that in the context of radially symmetric solutions, this problem exhibits an apparently novel type of critical mass phenomenon. In consequence,precisely at mass levels above a critical value $m_c$ the constant steadystates of the system possess the extreme instability property of repelling arbitrary concentration-increasing perturbations in sucha drastic sense that corresponding trajectories collapse in finite time.

报告主持：陶有山 教授

报告语言：英语