Shelling totally nonnegative flag varieties
نویسندگان
چکیده
منابع مشابه
Shelling Totally Nonnegative Flag Varieties
In this paper we study the partially ordered set Q of cells in Rietsch’s [20] cell decomposition of the totally nonnegative part of an arbitrary flag variety P ≥0 . Our goal is to understand the geometry of P ≥0 : Lusztig [13] has proved that this space is contractible, but it is unknown whether the closure of each cell is contractible, and whether P ≥0 is homeomorphic to a ball. The order comp...
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This note defines a flag vector for i-graphs. The construction applies to any finite combinatorial object that can be shelled. Two possible connections to quantum topology are mentioned. Further details appear in the author’s On quantum topology, hypergraphs and flag vectors, (preprint q-alg/9708001). The purpose of this note is to state concisely a new combinatorial concept. This note is an an...
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ژورنال
عنوان ژورنال: Journal für die reine und angewandte Mathematik (Crelles Journal)
سال: 2007
ISSN: 0075-4102,1435-5345
DOI: 10.1515/crelle.2007.059