details
Title
Étale groupoids as germ grupoids and their applications to coarse geometry
Abstract Every étale topological groupoid G gives rise to an inverse
semigroup equipped with a natural representation on the space of units
of G. The germs of such representation can be given the structure of an
étale groupoid which turns out to be isomorphic to G.
We extend this construction to `wide' inverse semigroups over a
topological space, which allows one to effectively construct étale
groupoid extensions by extending or modifying the underlying inverse
semigroup.
We use this machinery to construct an étale groupoid which is an
extension of a given groupoid in a way that its unit space is the
StoneČech compactification of the unit space of the given groupoid,
this extension generalizes the translation groupoid of Skandalis, Tu,
and Yu used in their study of the Novikov conjecture by coarse geometric
methods.
Speaker(s)
Dmitry Matsnev (IST)
Date
October 23, 2007 Time 14.45 Room
Sala 5.5
