Piercing intersecting convex sets

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Bárány, Imre, Dillon, Travis, Pálvölgyi, Dömötör, Varga, Dániel
Format: Preprint
Publié: 2024
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866910821140922368
author Bárány, Imre
Dillon, Travis
Pálvölgyi, Dömötör
Varga, Dániel
author_facet Bárány, Imre
Dillon, Travis
Pálvölgyi, Dömötör
Varga, Dániel
contents Assume two finite families $\mathcal A$ and $\mathcal B$ of convex sets in $\mathbb{R}^3$ have the property that $A\cap B\ne \emptyset$ for every $A \in \mathcal A$ and $B\in \mathcal B$. Is there a constant $γ>0$ (independent of $\mathcal A$ and $\mathcal B$) such that there is a line intersecting $γ|\mathcal A|$ sets in $\mathcal A$ or $γ|\mathcal B|$ sets in $\mathcal B$? This is an intriguing Helly-type question from a paper by Martínez, Roldan and Rubin. We confirm this in the special case when all sets in $\mathcal A$ lie in parallel planes and all sets in $\mathcal B$ lie in parallel planes; in fact, all sets from one of the two families has a line transversal.
format Preprint
id arxiv_https___arxiv_org_abs_2409_06472
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Piercing intersecting convex sets
Bárány, Imre
Dillon, Travis
Pálvölgyi, Dömötör
Varga, Dániel
Combinatorics
52A15, 52A35, 90C05
Assume two finite families $\mathcal A$ and $\mathcal B$ of convex sets in $\mathbb{R}^3$ have the property that $A\cap B\ne \emptyset$ for every $A \in \mathcal A$ and $B\in \mathcal B$. Is there a constant $γ>0$ (independent of $\mathcal A$ and $\mathcal B$) such that there is a line intersecting $γ|\mathcal A|$ sets in $\mathcal A$ or $γ|\mathcal B|$ sets in $\mathcal B$? This is an intriguing Helly-type question from a paper by Martínez, Roldan and Rubin. We confirm this in the special case when all sets in $\mathcal A$ lie in parallel planes and all sets in $\mathcal B$ lie in parallel planes; in fact, all sets from one of the two families has a line transversal.
title Piercing intersecting convex sets
topic Combinatorics
52A15, 52A35, 90C05
url https://arxiv.org/abs/2409.06472