English

Lower Bounds for Pinning Lines by Balls

Computational Geometry 2009-06-17 v1

Abstract

A line L is a transversal to a family F of convex objects in R^d if it intersects every member of F. In this paper we show that for every integer d>2 there exists a family of 2d-1 pairwise disjoint unit balls in R^d with the property that every subfamily of size 2d-2 admits a transversal, yet any line misses at least one member of the family. This answers a question of Danzer from 1957.

Cite

@article{arxiv.0906.2924,
  title  = {Lower Bounds for Pinning Lines by Balls},
  author = {Otfried Cheong and Xavier Goaoc and Andreas Holmsen},
  journal= {arXiv preprint arXiv:0906.2924},
  year   = {2009}
}
R2 v1 2026-07-22T20:51:37.842Z