时间：2019年4月6日
地点：北京师范大学后主楼1220
14：00—15：00
报告人：丁帆 （北京大学）
题目：Contact surgery: a survey
摘要：Contact surgery is a useful tool in the study of contact 3-manifolds. In this talk, I will first introduce some basic concepts in 3-dimensional contact topology such as Legendrian knot, convex surface, contact surgery, contact invariant. Then I will review some recent results on contact surgery.
15：30—16：30
报告人：苏阳 （中国科学院）
题目：有限循环群在高连通流形上的自由作用
摘要：在这个报告中我将介绍在一类最简单的高连通流形——球面乘积的连通和上的素数阶循环群的自由作用的分类。当素数大于一个只依赖于维数的常数时，我们可以得到完整的分类结果。这是一项与红河州大学杨建强合作的研究。
17：00—18：00
报告人：吕志 （复旦大学）
题目：On orbit braids
摘要：Let M be a connected topological manifold of dimension at least 2 with an effective action of a finite group G. Associated with the orbit configuration space of the G-manifold M, we give the notion of orbit braids and define the orbit braid group. We further study the subgroups of orbit braid group and various relations among these subgroups with the fundamental groups of the configuration spaces given by the manifold M with or without the G-action, and the M/G. We also calculate the orbit braid groups in the plane with two typical actions. This is a joint work with Hao Li and Fengling Li.
