Seminar in Real and Complex Geometry

Thursday, November 30, 2017, 11:00-12:00, Schreiber building, room 209

Giuliano Gagliardi (Tel Aviv)

The Luna-Vust theory of spherical embeddings


Let G be a connected reductive algebraic group over the field of complex numbers and let G/H be a spherical homogeneous space. A G-equivariant open embedding of G/H into an irreducible normal variety X is called a spherical embedding. Using the combinatorial invariants of G/H from the previous talk, a spherical embedding G/H -> X can be combinatorially described by its colored fan, which contains a colored cone for each G-orbit in X. In the special case of toric varieties, we recover the more widely known description of toric varieties in terms of cones and fans. This talk contains no new results and is based on Friedrich Knop's paper with the same title.