Oberseminar Geometrie, Topologie und Analysis

H. Geiges, A. Lytchak, G. Marinescu, S. Sabatini

Wintersemester 2018/19

Freitag, 10:30-11:30, Seminarraum 2 (Raum 204)

28.9.18 BGHK Seminar in Köln

19.10.18 BGHK Seminar in Bochum

26.10.18 Julie Rowlett (Göteborg)
Variational formulas for the Selberg zeta function and applications to curvature asymptotics

Abstract: We will begin by introducing the Selberg zeta function and its relatives. Next, we introduce the geometric setting of our work: the Teichmüller space of Riemann surfaces of genus g. The focus of this talk is the behavior of the Selberg zeta function Z(s) as a function on Teichmüller space. We will deduce an explicit formula for the second variation of Z(s) via a certain infinite sum involving lengths of closed geodesics of the underlying surfaces. Our variational formula and its asymptotics have interesting implications for the curvature of the Hodge bundle and its relationship to the Quillen curvature. The talk is intended for a general mathematical audience; if any of the aforementioned notions are unfamiliar, questions are most welcome and explanations shall be happily provided! Based on joint work with K. Fedosova and G. Zhang.
23.11.18 Joint Seminar on Complex Algebraic Geometry and Complex Analysis in Bochum

7.12.18 Tam Nguyen Phan (MPI Bonn)
Topology of ends of nonpositively curved manifolds

14.12.18 Grigori Avramidi (MPI Bonn)
On isometry groups preserving multiple horospheres

18.1.19 Joint Seminar on Complex Algebraic Geometry and Complex Analysis in Essen

Andreas Ott (Heidelberg)
Bounded cohomology in large degree

Abstract: I will discuss recent progress on the computation of the continuous bounded cohomology of Lie groups in large degree.

H. Geiges, 5.4.02