English

The Complex of Non-Crossing Diagonals of a Polygon

Combinatorics 2010-07-23 v1 Algebraic Topology

Abstract

Given a convex n-gon P in the Euclidean plane, it is well known that the simplicial complex \theta(P) with vertex set given by diagonals in P and facets given by triangulations of P is the boundary complex of a polytope of dimension n-3. We prove that for any non-convex polygonal region P with n vertices and h+1 boundary components, \theta(P) is a ball of dimension n+3h-4. We also provide a new proof that \theta(P) is a sphere when P is convex.

Keywords

Cite

@article{arxiv.0802.1320,
  title  = {The Complex of Non-Crossing Diagonals of a Polygon},
  author = {Benjamin Braun and Richard Ehrenborg},
  journal= {arXiv preprint arXiv:0802.1320},
  year   = {2010}
}

Comments

5 pages, submitted