English

Generalized laminar families and certain forbidden matrices

Combinatorics 2014-06-13 v1

Abstract

Recall that in a laminar family, any two sets are either disjoint or contained one in the other. Here, a parametrized weakening of this condition is introduced. Let us say that a set system F2X\mathcal{F} \subseteq 2^X is tt-laminar if A,BFA,B \in \mathcal{F} with ABt|A \cap B| \ge t implies ABA \subseteq B or BAB \subseteq A. We obtain very close asymptotic bounds in terms of nn on the maximum size of a 22-laminar family F2[n]\mathcal{F} \subseteq 2^{[n]}. A construction for 33-laminar families and a crude analysis for general tt are also given.

Keywords

Cite

@article{arxiv.1406.3077,
  title  = {Generalized laminar families and certain forbidden matrices},
  author = {Peter Dukes},
  journal= {arXiv preprint arXiv:1406.3077},
  year   = {2014}
}
R2 v1 2026-06-22T04:36:35.188Z