English

Every Large Point Set contains Many Collinear Points or an Empty Pentagon

Combinatorics 2011-01-04 v2 Computational Geometry

Abstract

We prove the following generalised empty pentagon theorem: for every integer 2\ell \geq 2, every sufficiently large set of points in the plane contains \ell collinear points or an empty pentagon. As an application, we settle the next open case of the "big line or big clique" conjecture of K\'ara, P\'or, and Wood [\emph{Discrete Comput. Geom.} 34(3):497--506, 2005].

Keywords

Cite

@article{arxiv.0904.0262,
  title  = {Every Large Point Set contains Many Collinear Points or an Empty Pentagon},
  author = {Zachary Abel and Brad Ballinger and Prosenjit Bose and Sébastien Collette and Vida Dujmović and Ferran Hurtado and Scott D. Kominers and Stefan Langerman and Attila Pór and David R. Wood},
  journal= {arXiv preprint arXiv:0904.0262},
  year   = {2011}
}
R2 v1 2026-06-21T12:47:18.070Z