English

Toric varieties modulo reflections

Combinatorics 2026-01-29 v2 Commutative Algebra Algebraic Geometry

Abstract

Let WW be a finite group generated by reflections of a lattice MM. If a lattice polytope PMZRP \subset M \otimes_{\mathbb Z}\mathbb R is preserved by WW, then we show that the quotient of the projective toric variety XPX_P by WW is isomorphic to the toric variety XPDX_{P \cap D}, where DD is a fundamental domain for the action of WW. This answers a question of Horiguchi-Masuda-Shareshian-Song, and recovers results of Blume, of Song, of the second author, and of Gui-Hu-Liu. We also study quotients of real toric varieties, proving that XPR/WX_P^{\mathbb R} / W is contractible when PP is a permutohedron.

Keywords

Cite

@article{arxiv.2410.14653,
  title  = {Toric varieties modulo reflections},
  author = {Colin Crowley and Tao Gong and Connor Simpson},
  journal= {arXiv preprint arXiv:2410.14653},
  year   = {2026}
}

Comments

added results on real points

R2 v1 2026-06-28T19:27:36.253Z