学术报告

题      目：Stability of rotating gaseous stars

报  告  人：王钰聪  博士  (邀请人：王勇 )

                                  北京大学

时      间：7月6日  15：00-17：00

地     点：数科院西楼二楼会议室

报告人简介:

        王钰聪，2021年6月获得厦门大学理学博士学位。毕业后于北京大学做博士后，主要从事描述气态星体模型的偏微分方程的稳定性方面研究。部分论文发表在国际重要学术期刊Commun. Math.Phys.

摘      要：

       We consider stability of rotating gaseous stars modeled by the Euler-Poisson system with general equation of states. When the angular velocity of the star is Rayleigh stable, we proved a sharp stability criterion for axi-symmetric perturbations. We also obtained estimates for the number of unstable modes and exponential trichotomy for the linearized Euler-Poisson system. By using this
stability criterion, we proved that for a family of slowly rotating stars parameterized by the center density with fixed angular velocity, the turning point principle is not true. That is, unlike the case of non-rotating stars, the change of stability of the rotating stars does not occur at extrema points
of the total mass. By contrast, we proved that the turning point principle is true for the family of slowly rotating stars with fixed angular momentum distribution. When the angular velocity is Rayleigh unstable, we proved linear instability of rotating stars. Moreover, we gave a complete description of the spectra and sharp growth estimates for the linearized Euler-Poisson system. This is a joint work with Zhiwu Lin.