Mathematisches Kolloquium
Am Donnerstag, 14.12.2023 um 16:30 Uhr spricht
Wolfgang Lück
(Universität Bonn
)
im Hörsaal über das Thema
Survey on aspherical manifolds
Abstract: We give a survey over aspherical closed manifolds. Aspherical is the purely homotopy theoretic condition that the universal covering is contractible. There are many well-known examples such as closed Riemannian manifolds with non-positive sectional curvature, but also very exotic examples such as closed aspherical manifolds that do not admit a triangulation. We discuss some prominent conjectures, e.g., the Borel Conjecture about the topological rigidity, and the Singer Conjecture about the concentration of L^2-Betti numbers in the middle dimension.