The largest Erdős-Ko-Rado sets in 2-(v,k,1) designs
arXiv:1601.00441 · doi:10.1007/s10623-014-9929-5
Abstract
An Erdős-Ko-Rado set in a block design is a set of pairwise intersecting blocks. In this article we study Erdős-Ko-Rado sets in 2-(v,k,1) designs, Steiner systems. The Steiner triple systems and other special classes are treated separately. For unitals we also determine an upper bound on the size of the second-largest maximal Erdos-Ko-Rado sets.