Prof. Dr. Wolfgang Lück, Universität Bonn, Vortrag: Homological growth and L^2-invariants
Donnerstag, 13.12.2012 16:30 im Raum M5
Abstract: There are basic invariants in algebraic topology such as the Euler
the Betti numbers, the signature, and Reidemeister and Ray-Singer torsion.
Given a tower of finite coverings that converges to the universal
covering, one may ask whether the sequence
of these classical invariants for the members of this tower (divided by
the number of sheets) converges.
In some interesting cases this is known to be true
and the limit in its own right is an interesting invariant, often an
There are very important cases where one has a good guess about the
limit but no proof is known.
After a gentle introduction to the classical invariants,
we discuss the relevance and the state of art concerning this problem
that has created a lot of activities in the recent years.