English

Merging divisorial with colored fans

Algebraic Geometry 2015-06-16 v3

Abstract

Given a spherical homogeneous space G/H of minimal rank, we provide a simple procedure to describe its embeddings as varieties with torus action in terms of divisorial fans. The torus in question is obtained as the identity component of the quotient group N/H, where N is the normalizer of H in G. The resulting Chow quotient is equal to (a blowup of) the simple toroidal compactification of G/(H N^0). In the horospherical case, for example, it is equal to a flag variety, and the slices (coefficients) of the divisorial fan are merely shifts of the colored fan along the colors.

Cite

@article{arxiv.1210.4523,
  title  = {Merging divisorial with colored fans},
  author = {Klaus Altmann and Valentina Kiritchenko and Lars Petersen},
  journal= {arXiv preprint arXiv:1210.4523},
  year   = {2015}
}

Comments

34 pages, 6 figures, final version to appear in Michigan Math. J

R2 v1 2026-06-21T22:22:53.459Z