English

Saturating sets in projective planes and hypergraph covers

Combinatorics 2017-11-28 v2

Abstract

Let Πq\Pi_q be an arbitrary finite projective plane of order qq. A subset SS of its points is called saturating if any point outside SS is collinear with a pair of points from SS. Applying probabilistic tools we improve the upper bound on the smallest possible size of the saturating set to 3qlnq+(q+1)/2\lceil\sqrt{3q\ln{q}}\rceil+ \lceil(\sqrt{q}+1)/2\rceil. The same result is presented using an algorithmic approach as well, which points out the connection with the transversal number of uniform multiple intersecting hypergraphs.

Keywords

Cite

@article{arxiv.1701.01379,
  title  = {Saturating sets in projective planes and hypergraph covers},
  author = {Zoltán Lóránt Nagy},
  journal= {arXiv preprint arXiv:1701.01379},
  year   = {2017}
}

Comments

10 pages, detailed calculations are included compared to V1

R2 v1 2026-06-22T17:42:08.216Z