Best possible bounds on the double-diversity of intersecting hypergraphs
Combinatorics
2025-02-26 v1
Abstract
For a family and two elements define . The double-diversity is defined as the minimum of over all pairs . Let consist of the seven lines of the Fano plane. For , one defines the Fano -graph as the collection of all -subsets of that contain at least one line. It is proven that for the Fano -graph is the essentially unique family maximizing the double diversity over all -graphs without a pair of disjoint edges. Some similar, although less exact results are proven for triple and higher diversity as well.
Keywords
Cite
@article{arxiv.2212.11650,
title = {Best possible bounds on the double-diversity of intersecting hypergraphs},
author = {Peter Frankl and Jian Wang},
journal= {arXiv preprint arXiv:2212.11650},
year = {2025}
}