English

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

Algebraic Geometry 2008-02-08 v1

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.

Keywords

Cite

@article{arxiv.0802.0889,
  title  = {The totally nonnegative part of G/P is a CW complex},
  author = {Konstanze Rietsch and Lauren Williams},
  journal= {arXiv preprint arXiv:0802.0889},
  year   = {2008}
}

Comments

14 pages

R2 v1 2026-06-21T10:10:14.901Z