报告人：余国巍

工作单位：南开大学

报告时间：11月8日上午9：00

报告地点：数学与统计学院北研究生教室

报告摘要:  

It is well-known that the N-center problem is chaotic when N ≥ 3. By regularizing collisions, one can associate the dynamics with a symbolic dynamical system which yields infinitely many periodic and chaotic orbits, possibly with collisions. it is a challenging task to construct chaotic orbits without any collision. In this talk we consider the planar N-center problem with collinear centers and N ≥ 3, and show that, for any fixed nonnegative energy and certain types of periodic free-time minimizers, there are infinitely many collision-free heteroclinic orbits connecting them. Our approach is based on minimization of a normalized action functional over paths within certain topological classes, and the exclusion of collision is based on some recent advances on local deformation methods. This is a joint work with Kuo-Chang Chen.

报告人简介：

余国巍，现任职于南开大学陈省身数学研究所。于美国明尼苏达大学数学系取得博士学位，曾在加拿大多伦多大学，法国巴黎九大及巴黎天文台，意大利都灵大学，美国数学科学研究所(MSRI)等科研机构从事数学研究工作。主要研究兴趣为动力系统，变分法，及其在天体力学上的应用。