On the Erdos-Ko-Rado Theorem and the Bollobas Theorem for t-intersecting families

TL;DR

This paper extends classical theorems on t-intersecting families of sets, providing strengthened bounds and a probabilistic proof for a generalized Bollobás theorem, broadening understanding of intersecting set families.

Contribution

It generalizes existing theorems on t-intersecting families, offering new bounds and a probabilistic proof for a Bollobás-type theorem for all t ≥ 1.

Findings

Strengthened bounds for t-intersecting families.

Generalized Bollobás Theorem for t-intersecting families.

Probabilistic proof technique for the generalized theorem.

Abstract

A family $\mathcal{F}$ is $t$-$\it{intersecting}$ if any two members have at least $t$ common elements. Erd\H os, Ko, and Rado proved that the maximum size of a $t$-intersecting family of subsets of size $k$ is equal to $ {{n-t} \choose {k-t}}$ if $n\geq n_0(k,t)$. Alon, Aydinian, and Huang considered families generalizing intersecting families, and proved the same bound. In this paper, we give a strengthening of their result by considering families generalizing $t$-intersecting families for all $t \geq 1$. In 2004, Talbot generalized Bollob\'{a}s's Two Families Theorem to $t$-intersecting families. In this paper, we proved a slight generalization of Talbot's result by using the probabilistic method.