Essays on Coxeter groups Bruhat closures
نویسنده
چکیده
If G is a split reductive group and B a Borel subgroup then G is the disjoint union of the BwB as w ranges over the Weyl group of a maximal torus in B. The closure of BwB is the union of certain double cosets BxB, where the x that occur can be characterized in purely combinatorial terms. Somewhat surprisingly, this combinatorial definition may be extended to define the Bruhat closure operation in any Coxeter group.
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