Speaker：Huagui Duan（Nankai University）

Time：2022-12-08, 16:30

Location：Tencent Meeting ID：982-549-430（No Password）

Abstract:

In this talk, I will introduce two classes of periodic orbits, i.e., closed geodesics on compact manifolds and closed characteristics on hypersurfaces with fixed energy in $R^{2n}$. Then I will simply explain how to obtain some results about lower bound of the number of periodic orbits by using the index theory and some variational methods.