The complex of non-crossing diagonals of a polygon

  • Authors:
  • Benjamin Braun;Richard Ehrenborg

  • Affiliations:
  • Department of Mathematics, University of Kentucky, Lexington, KY, United States;Department of Mathematics, University of Kentucky, Lexington, KY, United States

  • Venue:
  • Journal of Combinatorial Theory Series A
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

Given a convex n-gon P in R^2 with vertices in general position, it is well known that the simplicial complex @q(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, @q(P) is a ball of dimension n+3h-4. We also provide a new proof that @q(P) is a sphere when P is convex with vertices in general position.