English

A note on saturation for $k$-wise intersecting families

Combinatorics 2022-09-21 v2

Abstract

A family F\mathcal{F} of subsets of {1,,n}\{1,\dots,n\} is called kk-wise intersecting if any kk members of F\mathcal{F} have non-empty intersection, and it is called maximal kk-wise intersecting if no family strictly containing F\mathcal{F} satisfies this condition. We show that for each k2k\geq 2 there is a maximal kk-wise intersecting family of size O(2n/(k1))O(2^{n/(k-1)}). Up to a constant factor, this matches the best known lower bound, and answers an old question of Erd\H{o}s and Kleitman, recently studied by Hendrey, Lund, Tompkins, and Tran.

Keywords

Cite

@article{arxiv.2111.12021,
  title  = {A note on saturation for $k$-wise intersecting families},
  author = {Barnabás Janzer},
  journal= {arXiv preprint arXiv:2111.12021},
  year   = {2022}
}

Comments

4 pages; added a new section about the non-existence of certain types of constructions

R2 v1 2026-06-24T07:49:22.418Z