English

Combinatorial pseudo-Triangulations

Combinatorics 2007-05-24 v3 Metric Geometry

Abstract

We prove that a planar graph is generically rigid in the plane if and only if it can be embedded as a pseudo-triangulation. This generalizes the main result of math.CO/0307347 which treats the minimally generically rigid case. The proof uses the concept of combinatorial pseudo-triangulation, CPT, in the plane and has two main steps: showing that a certain ``generalized Laman property'' is a necessary and sufficient condition for a CPT to be ``stretchable'', and showing that all generically rigid plane graphs admit a CPT assignment with that property. Additionally, we propose the study of combinatorial pseudo-triangulations on closed surfaces.

Keywords

Cite

@article{arxiv.math/0307370,
  title  = {Combinatorial pseudo-Triangulations},
  author = {David Orden and Francisco Santos and Brigitte Servatius and Herman Servatius},
  journal= {arXiv preprint arXiv:math/0307370},
  year   = {2007}
}

Comments

17 pages, 10 figures. Changes from v2: minor editing plus removal of a superfluous lemma. Changes from v1: Section 5 has been completely rewritten, after a referee complained (rightfully) that too many details were omitted. The rest only has minor corrections and stylistic changes. This version has been accepted in "Discrete Mathematics"