On the random version of the Erdős matching conjecture

Abstract

The Kneser hypergraph KGn,kr is an r-uniform hypergraph with vertex set consisting of all k-subsets of {1,…,n} and any collection of r vertices forms an edge if their corresponding k-sets are pairwise disjoint. The random Kneser hypergraph KGn,kr(p) is a spanning subhypergraph of KGn,kr in which each edge of KGn,kr is retained independently of each other with probability p. The independence number of random subgraphs of KGn,k2 was recently addressed in a series of works by Bollobás et al. (2016), Balogh et al. (2015), Das and Tran (2016) and Devlin and Kahn (2016). It was proved that the random counterpart of the Erdős–Ko–Rado theorem continues to be valid even for very small values of p. In this paper, generalizing this result, we will investigate the independence number of random Kneser hypergraphs KGn,kr(p). Broadly speaking, when k is much smaller that n, we will prove that the random analogue of the Erdős matching conjecture is true even for extremely small values of p.