Let G be a simply connected semisimple algebraic group over an algebraically closed field k of characteristic 0 and let V be a rational simple G-module. If G/H aS, P(V) is a spherical orbit and if X = (G/H) over bar is its closure, then we describe the orbits of X and those of its normalization (X) over tilde. If, moreover, the wonderful completion of G/H is strict, then we give necessary and sufficient combinatorial conditions so that the normalization morphism (X) over tilde -> X is a homeomorphism. Such conditions are trivially fulfilled if G is simply laced or if H is a symmetric subgroup.
|Titolo:||Spherical orbit closures in simple projective spaces and their normalizations|
|Data di pubblicazione:||2011|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s00031-011-9120-2|
|Appare nelle tipologie:||1.1 Articolo in rivista|