报告时间：2026年9月3日（周四）上午 09:30-10:25
报告地点：苏州大学天赐庄校区纯水楼301
报告人：段华贵 教授，吉林大学
报告摘要：
For hypersurfaces in $T^*S^n$, the dynamical convexity yields at least $[\frac{n+1}{2}]$ closed Reeb orbits; with non-degeneracy and finitely many orbits, at least two orbits are irrationally elliptic. For star-shaped hypersurfaces in $R^{2n}$, a weakened index condition implies that all closed orbits are non-hyperbolic. In $R^6$ with exactly three non-degenerate closed characteristics and no index-1 orbit, all of them are elliptic and not locally maximal. Additionally, under dynamical convexity, no closed Reeb orbit can be both non-degenerate and locally maximal. These results are based on recent joint works with Zihao Qi.
报告人简介：
段华贵，现为吉林大学教授，博导，研究方向为哈密顿动力系统与辛几何。近年来，在Maslov-型指标迭代理论、哈密顿系统的周期轨道和微分几何中的闭测地线等方面取得系统性的研究成果，研究成果发表在JDG，J. Reine Angew. Math.（Crelle）, Adv. Math., TAMS, JFA，Math. Z.等国际数学期刊上。
邀请人：杨大伟