pith. sign in

arxiv: 1406.3077 · v1 · pith:5K4ZCMCCnew · submitted 2014-06-11 · 🧮 math.CO

Generalized laminar families and certain forbidden matrices

classification 🧮 math.CO
keywords laminarsubseteqmathcalfamiliesfamilyanalysisasymptoticbounds
0
0 comments X
read the original 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 $\mathcal{F} \subseteq 2^X$ is $t$-laminar if $A,B \in \mathcal{F}$ with $|A \cap B| \ge t$ implies $A \subseteq B$ or $B \subseteq A$. We obtain very close asymptotic bounds in terms of $n$ on the maximum size of a $2$-laminar family $\mathcal{F} \subseteq 2^{[n]}$. A construction for $3$-laminar families and a crude analysis for general $t$ are also given.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.