题目：On degenerate partial differential equations

主讲：Ingo Witt教授

时间：2017年10月9日（周一）下午15：00

地点：物理实验中心E202

主办：数理部

Ingo Witt教授简介：博士生导师，洪堡大学学士，波恩大学博士，曾在欧美等多所世界著名高校任职，现为德国哥廷根大学全职教授。担任《Journal of Pseudo-Differential Operators and Applications》《International Journal of Mathematics and Mathematical Sciences》《Advance in Partial Differential Equations》等学术期刊编委，发表高质量SCI论文数十篇，编著文献书籍多部。

报告主要内容：Degenerate partial differential equations (PDEs) constitute a particular challenge in the general theory of PDEs. This is despite the fact that they often arise in applications. The usual approach to PDEs consists in assigning a type to an equation (like elliptic, hyperbolic, and parabolic) and then to study whole classes of equations simultaneously. In the degenerate case, this approach does not work any longer, as certain characteristics defining these classes of PDEs degenerate (or become singular) at certain points of the underlying domain. This has, for instance, the effect that certain constants in estimates fundamental for the theory explode at those special points.In this talk, we will discuss a number of strategies still to deal with degenerate PDEs and to reach conclusive results.