English

Union-intersecting set systems

Combinatorics 2014-03-04 v1

Abstract

Three intersection theorems are proved. First, we determine the size of the largest set system, where the system of the pairwise unions is l-intersecting. Then we investigate set systems where the union of any s sets intersect the union of any t sets. The maximal size of such a set system is determined exactly if s+t<5, and asymptotically if s+t>4. Finally, we exactly determine the maximal size of a k-uniform set system that has the above described (s,t)-union-intersecting property, for large enough n.

Keywords

Cite

@article{arxiv.1403.0088,
  title  = {Union-intersecting set systems},
  author = {Gyula O. H. Katona and Dániel T. Nagy},
  journal= {arXiv preprint arXiv:1403.0088},
  year   = {2014}
}

Comments

9 pages

R2 v1 2026-06-22T03:18:19.724Z