English

The dual complex of $\bar{M}_{0,n}$ via phylogenetics

Algebraic Geometry 2016-05-10 v3

Abstract

The moduli space Mˉ0,n\bar{M}_{0,n} of stable rational n-pointed curves has divisorial boundary with simple normal crossings. In this brief note I observe that the dual complex is a flag complex; that is, a collection of irreducible boundary divisors has nonempty intersection if and only if the pairwise intersections are nonempty. Rather than proving this directly, I translate the statement to a setting in phylogenetics where it is widely used and multiple explicit proofs have been written. It appears this result is known by experts but lacks a detailed reference in the literature, except recently for n=7n=7.

Keywords

Cite

@article{arxiv.1512.00323,
  title  = {The dual complex of $\bar{M}_{0,n}$ via phylogenetics},
  author = {Noah Giansiracusa},
  journal= {arXiv preprint arXiv:1512.00323},
  year   = {2016}
}

Comments

3 pages; final version, to appear in Archiv der Mathematik