Speaker :	Professor Raphael Ponge (University of Tokyo)
Title :	Noncommutative geometry and lower dimensional volumes in Riemannian geometry
Time :	2011-05-02 (Mon) 16:10 - 17:00
Place :	Seminar Room 617, Institute of Mathematics (NTU Campus)
Abstract:	In this talk, I shall explain how to define "lower dimensional'' volumes of any compact Riemannian manifold as the integrals of local Riemannian invariants. For instance, it can be given sense to the area and the length of such a manifold in any dimension. The reasoning is motivated by an idea of Connes and involves in an essential way noncommutative geometry and the analysis of Dirac operators on spin manifolds. However, the ultimate definitions of the lower dimensional volumes do not involve noncommutative geometry or spin structures at all.