Am 29. Juni 2026 findet am Institut für Mathematik das Kolloquium des SFB-TRR 358 statt. Die Vortragenden sind Hans-Joachim Hein (Universität Münster) und Wolfgang Lück (Universität Bonn).
Programm:
15:00 - 16:00 Vortrag 1: Hans-Joachim Hein
16:00 - 16:45 Kaffeepause
16:45 - 17:45 Vortrag 2: Wolfgang Lück
17:45 Empfang
Ort:
Die Vorträge finden im Hörsaal D1 statt. Die Kaffeepause und der Empfang werden im Raum J2.138 stattfinden.
Hier finden Sie den Campus Lageplan.
Hans-Joachim Hein (Universität Münster)
Title: Riemannian geometry of Kähler manifolds
Abstract: Kähler manifolds are a class of Riemannian manifolds generalizing Riemann surfaces to higher dimensions. The most natural examples are complex projective algebraic manifolds together with the restriction of the Fubini-Study metric from CP^N. I will review the classical Uniformization Theorem for compact Riemann surfaces and its extension to higher-dimensional Kähler manifolds due to Calabi, Aubin and Yau in the 1970s. Then I will discuss some recent results aimed at understanding the geometric meaning of the Ricci curvature of a Kähler manifold, including work on the Positive Mass Theorem as well as some aspects of negative Kähler-Einstein manifolds generalizing the Teichmüller theory of hyperbolic Riemann surfaces.
Wolfgang Lück (Universität Bonn)
Title: An introduction to L^2-invariants
Abstract: Betti numbers of closed manifolds or finite simplicial complexes are classical invariants in algebraic topology.
Atiyah proposed an L^2-version obtained from the universal covering and the action of the fundamental group
using von Neumann algebras. We will present the basic properties of these L^2-Betti numbers
and discuss applications to topology, algebra, group theory, and geometry which are both interesting and not hard to explain.
Finally we give an outlook on the current research problems about L^2-invariants.
