Affine spherical homogeneous spaces with good quotient by a maximal unipotent subgroup

Roman Avdeev

Published 2011-06-28, updated 2013-01-14Version 3

For an affine spherical homogeneous space G/H of a connected semisimple algebraic group G, we consider the factorization morphism by the action on G/H of a maximal unipotent subgroup of G. We prove that this morphism is equidimensional if and only if the weight semigroup of G/H satisfies some simple condition.