English

On the number of drawings of a combinatorial triangulation

Combinatorics 2025-04-25 v1

Abstract

In 1962, Tutte provided a formula for the number of combinatorial triangulations, that is, maximal planar graphs with a fixed triangular face and nn additional vertices. In this note, we study how many ways a combinatorial triangulation can be drawn as geometric triangulation, that is, with straight-line segments, on a given point set in the plane. Our central contribution is that there exists a combinatorial triangulation with n vertices that can be drawn in at least Ω(1,31n)\Omega(1,31^n) ways on a set of n points as different geometric triangulations. We also show an upper bound on the number of drawings of a combinatorial triangulation on the so-called double chain point set.

Keywords

Cite

@article{arxiv.2504.17088,
  title  = {On the number of drawings of a combinatorial triangulation},
  author = {Belén Cruces and Clemens Huemer and Dolores Lara},
  journal= {arXiv preprint arXiv:2504.17088},
  year   = {2025}
}