一、题目: The period function of Hamiltonian systems with separable variables
二、主讲人：张祥教授
三、时 间：2019年11月02日（周六） 下午15:300 —16：10
四、地 点：闻理园A4--305室
报告摘要: In this talk we intrudoce our recent results on the period function of planar Hamiltonian differential systems with separable variables. More concretely we are concerned with the search of sufficient conditions implying the monotonicity of the period function, i.e., the absence of critical periodic orbits. We are also interested in the uniqueness problem and in this respect we seek conditions implying that there exists at most one critical periodic orbit. We obtain in a unified way several sufficient conditions that already appear in the literature, together with some other results that to the best of our knowledge are new. Finally we also investigate the limit of the period function as the periodic orbits tend to the boundary of the period annulus of the center.
报告人简介：张祥，欧洲科学与艺术院院士，上海交通大学特聘教授，博士生导师；享受国务院政府特殊津贴专家；入选教育部新世纪优秀人才和上海市曙光人才。主要从事常微分方程的定性、分支和动力可积理论的研究。
现担任中国数学会奇异摄动专业委员会常务副理事长,中国数学会理事以及 Qualitative Theory of Dynamical Systems 和 International J. Bifurcation and Chaos 等SCI杂志的副主编。
自1999年以来，连续主持国家自然科学基金项目或参加国家自然科学基金重点项目。
主要结果发表在American J. Mathematics, Transactions of Amer. Math. Soc., Communications Math. Physics, J. Functional Analysis, Physica D, J. Nonlinear Science, J. Differential Equations和Ergodic Theoery and Dynamical Systems等国际核心期刊上。
欢迎广大师生参加！联系人：李先义
理学院/大数据学院
非线性研究所
2019年10月28日
