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arXiv · 0802.0889

The totally nonnegative part of G/P is a CW complex

Konstanze Rietsch·Lauren Williams
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Abstract

The totally nonnegative part of a partial flag variety G/P has been shown by the first author to be a union of semi-algebraic cells. Moreover she showed that the closure of a cell is the union of smaller cells. In this note we provide glueing maps for each of the cells to prove that the totally nonnegative part of G/P is a CW complex. This generalizes a result of Postnikov, Speyer and the second author for Grassmannians.

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Konstanze Rietsch, Lauren Williams. 2008-02-07. The totally nonnegative part of G/P is a CW complex. https://arxiv.org/abs/0802.0889

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