On Orbit Closures of Symmetric Subgroups in Ag Varieties
نویسنده
چکیده
Introduction Let G be a connected reductive group over an algebraically closed eld k; let B G be a Borel subgroup and K G a closed subgroup. Assume that K is a spherical subgroup of G, that is, the number of K-orbits in the ag variety G=B is nite; equivalently, the set KnG=B of (K; B)-double cosets in G is nite. Then the following problems arise naturally.
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