English

Residual $q$-Fano Planes and Related Structures

Combinatorics 2017-11-21 v2

Abstract

One of the most intriguing problems, in qq-analogs of designs, is the existence question of an infinite family of qq-analog of Steiner systems, known also as qq-Steiner systems, (spreads not included) in general, and the existence question for the qq-analog of the Fano plane, known also as the qq-Fano plane, in particular. These questions are in the front line of open problems in block design. There was a common belief and a conjecture that such structures do not exist. Only recently, qq-Steiner systems were found for one set of parameters. In this paper, a definition for the qq-analog of the residual design is presented. This new definition is different from previous known definition, but its properties reflect better the qq-analog properties. The existence of a design with the parameters of the residual qq-Steiner system in general and the residual qq-Fano plane in particular are examined. We prove the existence of the residual qq-Fano plane for all qq, where qq is a prime power. The constructed structure is just one step from a construction of a qq-Fano plane.

Keywords

Cite

@article{arxiv.1704.07714,
  title  = {Residual $q$-Fano Planes and Related Structures},
  author = {Tuvi Etzion and Niv Hooker},
  journal= {arXiv preprint arXiv:1704.07714},
  year   = {2017}
}