报告一

报告题目：Existence of Rotating Stars with Variable Entropy

报告人：Wu Yilun （University of Oklahoma）

时间：6月5日（周三）下午14:00-15:00   地点：理科楼B302

摘要：Rotating stars can be modeled by steady solutions to the Euler-Poisson equations. An extensive literature has established the existence of rotating stars for given differentially rotating angular velocity profiles. However, all of the existing results require the angular velocity to depend on the distance to the rotation axis, but not on the distance to the equatorial plane. Incidentally, all of these solutions have constant entropy within the star. In this talk, I will present a recent result which is the first that allows a general rotation profile, without restrictions. It is also the first result that allows genuinely changing entropy within the star. The variation of entropy causes the previous methods used to construct steady solutions inapplicable. We discover a div-curl reformulation of the problem and perform analysis on the resulting elliptic-hyperbolic system. This is joint work with Juhi Jang and Walter Strauss.

报告二

报告题目：The modulational approximation to the water waves

报告人：苏庆堂 副研究员 （中国科学院数学与系统科学研究院）

时间：6月5日（周三）下午15:00-16:00        地点：理科楼B302

摘要：In this talk I will discuss the modulational approximation in particular the NLS approximation to the irrotational and incompressible water waves. In particular, I will show how to use this to study the Benjamin-Feir instability of the Stokes waves in 2d water waves.

报告人简介：苏庆堂，博士毕业于密歇根大学安娜堡分校，目前为中国科学院数学与系统科学研究院优秀青年副研究员。主要研究工作涉及水波方程长时间行为的严格数学分析，在有旋水波的长时间行为、Rayleigh-Taylor不稳定性跃迁等问题取得了进展。

邀请人：曾惠慧