Matsuki's double coset decomposition via gradient maps
arXiv:0712.3384
Abstract
Let be a real-reductive Lie group and let and be two subgroups given by involutions. We show how the technique of gradient maps can be used in order to obtain a new proof of Matsuki's parametrization of the closed double cosets by Cartan subsets. We also describe the elements sitting in non-closed double cosets.
19 pages