English

Dihedral sign patterns in $\mathcal{M}_{0,n}$

Combinatorics 2025-09-05 v2 Algebraic Geometry

Abstract

The connected components of M0,n(R)\mathcal{M}_{0,n}(\mathbb{R}) are in bijection with the (n1)!/2(n-1)!/2 dihedral orderings of [n][n]. They are all isomorphic. We construct monomial maps between them, and use these maps to prove a conjecture of Arkani-Hamed, He, and Lam in the case of M0,n\mathcal{M}_{0,n}. Namely, we provide a bijection between connected components and sign patterns that are consistent with the extended uu-relations for the dihedral embedding.

Keywords

Cite

@article{arxiv.2508.14714,
  title  = {Dihedral sign patterns in $\mathcal{M}_{0,n}$},
  author = {Veronica Calvo Cortes and Hannah Tillmann-Morris},
  journal= {arXiv preprint arXiv:2508.14714},
  year   = {2025}
}

Comments

19 pages, 5 figures, 4 tables. Comments welcome!

R2 v1 2026-07-01T04:58:30.187Z