Mathematics Colloquium: Wolfgang Lück

Mathematics Colloquium with Wolfgang Lück

Join the Mathematics Colloquium with Wolfgang Lück from the University of Bonn in Germany, who will talk about L2-Betti numbers.

Betti numbers of closed manifolds or finite simplicial complexes are classical invariants in algebraic topology. Atiyah proposed an L2-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 L2-Betti numbers and discuss applications to topology, algebra, group theory, and geometry which are both interesting and not hard to explain.