题目：Instabilities for elliptic points and quasi-periodic tori in real analytic Hamiltonian dynamics.

报告人：Prof. Bassam Fayad  (巴黎七大)  

Abstract : We study the stability of  elliptic points and quasi-periodic tori in real analytic Hamiltonian dynamics, from 3 points of view : topologic, metric, and effective. We introduce in particular new diffusion mechanisms that yield the first examples of unstable non resonant elliptic fixed points and quasi-periodic tori. The Birkhoff normal forms at the fixed points are divergent while the BNF at the tori can be chosen to be divergent or convergent.

时间：4月9日星期二下午14:30-15:30

地点：565net必赢客户端教二楼808教室

联系人：孙善忠

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