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

Abstract

A family $\mathcal{F}$ is $t$-$intersecting$ 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 $\left(\genfrac{}{}{0ex}{}{n-t}{k-t}\right)$ if $n\ge n_0(k,t)$. 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 $t\ge 1$. In 2004, Talbot generalized Bollobás'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.