English

Steiner triple systems and spreading sets in projective spaces

Combinatorics 2021-03-02 v1

Abstract

We address several extremal problems concerning the spreading property of point sets of Steiner triple systems. This property is closely related to the structure of subsystems, as a set is spreading if and only if there is no proper subsystem which contains it. We give sharp upper bounds on the size of a minimal spreading set in a Steiner triple system and show that if all the minimal spreading sets are large then the examined triple system must be a projective space. We also show that the size of a minimal spreading set is not an invariant of a Steiner triple system.

Keywords

Cite

@article{arxiv.2103.00922,
  title  = {Steiner triple systems and spreading sets in projective spaces},
  author = {Zoltán Lóránt Nagy and Levente Szemerédi},
  journal= {arXiv preprint arXiv:2103.00922},
  year   = {2021}
}
R2 v1 2026-06-23T23:36:46.568Z