Speaker
Prof.
Hessel Posthuma
Description
This talk is based on joint work with Paolo Piazza, Yanli Song and Xiang Tang and expands on (but is independent of) the talk of Paolo Piazza. Given a proper, cocompact action of a connected, linear real reductive group, we define a delocalized eta-invariants of invariant Dirac operators. We then explain how these invariants enter as boundary correction terms in a APS-type index theorem. For pure Dirac operators this works under an L^2-invertibility assumption of the boundary operator, and we also discuss different types of perturbations of Dirac operators to remove this assumption.
