Speaker: Ilesanmi Adeboye, Wesleyan University

Title: Lower bounds for the covolume of lattices of semi-simple Lie groups

Abstract: A classic theorem of Kazhdan and Margulis states that for any semi-simple Lie group without compact factors, there is a positive lower bound on the co-volume of lattices. A direct consequence is a positive minimum volume for orbifolds modeled on the corresponding symmetric space. In this talk, I will construct an improved upper bound for the sectional curvature of a semi-simple Lie group. I will also show how H. C. Wang’s quantitative analysis of the Kazhdan-Margulis result can be extended to the exceptional Lie groups. These elements will then be used to establish a uniform lower bound for arbitrary orbifold quotients of symmetric spaces of non-compact type.

Department of Mathematical Sciences
George Mason University
4400 University Drive, MS 3F2
Fairfax, VA 22030-4444
http://math.gmu.edu/
Tel. 703-993-1460, Fax. 703-993-1491