Maximal semigroups in semi-simple Lie groups
Maximal semigroups in semi-simple Lie groups
The maximal semigroups with nonempty interior in a semi-simple Lie group with finite center are characterized as compression semigroups of subsets in the flag manifolds of the group. For this purpose a convexity theory, called here $\mathcal {B}$-convexity, based on the open Bruhat cells is developed. It turns out that …