学术报告
报告1
报告人：
冯惠涛 教授（重庆理工大学数学与统计学院）
报告题目:
A Poincare-Hopf type formula for complex-valued vector fields
报告时间：
7
月19日(周二)下午1：30～2：20
报告地点
：创新园大厦A1101
报告2
报告人：
韩飞 博士（新加坡国立大学数学系）
报告题目:
On Generalized Witten Genus
报告时间：
7
月19日（周二）下午2：30～3：20
报告地点：
创新园大厦A1101
摘要:
Witten genus is the loop space analogue of the Hirzebruch A-hat genus. On a string manifold, the Witten genus is a modular form and is the equivariant index of the S^1-equivariant Dirac operator on the free loop space. The homotopy refinement of the Witten genus leads to the theory of TMF (topological modular forms). Hohn and Stolz also conjectured that existence of a positive Ricci curvature metric on a string manifold implies the vanishing of the Witten genus. In this talk, I will discuss extensions of the classical Witten genus. One concerns a generalization of string manifolds, which we call string^c manifolds and the other one is the mod 2 extension. We will present vanishing results for these generalized Witten genera on complete intersections and describe a possible mod 2 extension of the Hohn-Stolz conjecture. The talk is based on the joint work with Chen Qingtao and Zhang Weiping.
另，原定Roman Mikhailov的7月8日下午系列讲座的时间由3：00～5：00调整为3：30～5：30，请周知。
本次系列学术报告联系人：雷逢春 教授
bg视讯
