Abstract
We prove that every finite family of convex sets in the plane satisfying the (4, 3)-property can be pierced by nine points. This improves the bound of 13 proved by Kleitman et al. (Combinatorica 21(2), 221–232 (2001)).
Similar content being viewed by others
References
Alon, N., Kleitman, D.J.: Piercing convex sets and the Hadwiger–Debrunner \((p, q)\)-problem. Adv. Math. 96(1), 103–112 (1992)
Hadwiger, H., Debrunner, H.: Über eine Variante zum Hellyschen Satz. Arch. Math. (Basel) 8, 309–313 (1957)
Helly, E.: Über Mengen konvexer Körper mit gemeinschaftlichen Punkten. Jahresber. Deutsch. Math. Verein. 32, 175–176 (1923)
Keller, Ch., Smorodinsky, S., Tardos, G.: Improved bounds on the Hadwiger–Debrunner numbers. Israel J. Math. 225(2), 925–945 (2018)
Kleitman, D.J., Gyárfás, A., Tóth, G.: Convex sets in the plane with three of every four meeting. Combinatorica 21(2), 221–232 (2001)
Knaster, B., Kuratowski, C., Mazurkiewicz, S.: Ein Beweis des Fixpunktsatzes für \(n\)-dimensionale Simplexe. Fundam. Math. 14, 132–137 (1929)
Lassonde, M.: Sur le principe KKM. C. R. Acad. Sci. Paris Sér. I Math. 310(7), 573–576 (1990)
Tardos, G.: Transversals of \(2\)-intervals, a topological approach. Combinatorica 15(1), 123–134 (1995)
Acknowledgements
The author would like to thank Shira Zerbib for many helpful remarks and for improving the overall presentation of this paper. The author would also like to thank the anonymous referees. Their comments led to improved notation and overall readability of this paper, including a simpler proof of Lemma 3.4.
Author information
Authors and Affiliations
Corresponding author
Additional information
Editor in Charge: Csaba D. Tóth
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
The author was supported by NSF Grant DMS-1839918 (RTG).
Rights and permissions
About this article
Cite this article
McGinnis, D. A Family of Convex Sets in the Plane Satisfying the (4, 3)-Property can be Pierced by Nine Points. Discrete Comput Geom 68, 860–880 (2022). https://doi.org/10.1007/s00454-022-00391-y
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00454-022-00391-y