Colloquium abstracts

Marco Antei
University of Lille, France
January 21, 2010

Galois closure of essentially finite morphisms:  Let X be a scheme over a field k and f:Y-->X an essentially finite morphism. We construct a "Galois closure" of f, i.e. the smallest possible torsor dominating it. As an application we construct the Galois closure of towers of torsors. (Work in collaboration with Michel Emsalem).