A note on infinite versions of $(p,q)$-theorems
Combinatorics
2024-12-06 v1
Abstract
We prove that fractional Helly and -theorems imply -theorems in an entirely abstract setting. We give a plethora of applications, including reproving almost all earlier -theorems about geometric hypergraphs that were proved recently. Some of the corollaries are new results, for example, we prove that if is an infinite family of convex compact sets in and among every of the sets some contain a point in their intersection with integer coordinates, then all the members of can be hit with finitely many points with integer coordinates.
Keywords
Cite
@article{arxiv.2412.04066,
title = {A note on infinite versions of $(p,q)$-theorems},
author = {Attila Jung and Dömötör Pálvölgyi},
journal= {arXiv preprint arXiv:2412.04066},
year = {2024}
}
Comments
A previous version of this work appeared as part of arXiv:2311.15646 (v1 and v2). The main theorem is included there, but the current version provides a clearer presentation and additional applications