主讲人：林治武，Professor of Georgia Institute of Technology
时间：2020年10月26日9:00
地点：腾讯会议 474 212 226
举办单位：数理学院
主讲人介绍：林治武教授，1995年本科毕业于北京大学、1999年硕士毕业于日本东京大学，在2003年美国布朗大学取得博士学位，并在著名的应用数学研究中心美国纽约大学柯朗应用数学研究所做博士后研究，现任美国乔治亚理工学院（Georgia Institute of Technology）数学系终身教授。主要研究领域: 数学物理与偏微分方程、流体动力学稳定性及不稳定性理论，在《Invent. Math.》、《Comm. Pure Appl. Math.》、《Memoirs of The American Mathematical Society》《Comm. Math. Phys.》和《Arch. Ration. Mech. Anal.》等权威期刊上发表30余篇学术论文。
内容介绍：I will discuss some recent results (with Chongchun Zeng) on stability criterion for non-rotating gaseous stars modeled by the Euler-Poisson system. Under general assumptions on the equation of states, we proved a turning point principle that the stability of the stars is entirely determined by the mass-radius curve parametrized by the center density. In particular, the stability can only changed at points with an extremal mass. We use a combination of first order and 2nd order Hamiltonian formulations to get the stability criterion and the semi-group estimates for the linearized equation. If time permits, I will briefly describe the extension of this approach to study stability of rotating stars, and relativistic stars and star clusters.