题 目: Characteristic class and the epsilon factor of a constructible \'etale sheaf
报告人： 阳恩林 博士 （德国Regensburg大学）
摘 要: In this talk, we will firstly recall the definitions and the properties of singular support and characteristic cycle of a constructible \'etale sheaf on a smooth variety. The singular support, defined by Beilinson, is a closed conical subset of the cotangent bundle.The characteristic cycle, constructed by Saito, is a $\mathbb Z$-linear combination of irreducible components of the singular support.This theory is an algebraic analogue of that studied by Kashiwara and Schapira in a transcendental setting.
In the second part of this talk we will focus on the joint work with Umezaki.We prove a conjecture of Kato-Saito on a twist formula for the epsilon factor of a constructible \'etale sheaf on a projective smooth variety over a finite field. In our proof, Beilinson and Saito's theory plays an essential role.
时 间：4月2日 下午7:00
邀请人： 秦厚荣 老师