There are many 5-holes
Combinatorics
2026-03-20 v1
Abstract
Given a set P of points on the plane, a polygon with vertices in P is said to be empty if it contains no element of P in its interior. We show that every set of n points in general position on the plane determines at least empty convex pentagons (also known as 5-holes). This result improves upon the previous bound of obtained by Aicholzer et al. [JCT A, 2020], and significantly narrows the gap with respect to the conjectured lower bound (which, if true, would be tight). Unlike some of the other works in this line of research, our proof does not require computer assistance.
Cite
@article{arxiv.2603.18484,
title = {There are many 5-holes},
author = {Omar Astudillo-Marbán and Oriol Solé-Pi},
journal= {arXiv preprint arXiv:2603.18484},
year = {2026}
}
Comments
17 pages, 11 figures