English

Two disguises of the linear representation of a subgeometry

Combinatorics 2021-12-24 v1

Abstract

Let PG(n,q)\text{PG}(n,q) be the Desarguesian projective space of dimension nn over the finite field of order qq. The \emph{linear representation} of a point set K\mathcal{K} in a hyperplane at infinity of PG(n,q)\text{PG}(n,q) is the point-line geometry consisting of the affine points of PG(n,q)\text{PG}(n,q), together with the union of the parallel classes of affine lines corresponding to the points of K\mathcal{K}. This type of point-line geometry has been widely investigated in the literature. Curiously, if K\mathcal{K} is a subgeometry, two disguises of its linear representation occur in two separate works. In this short note, we give an explicit isomorphism between these two disguises by making use of field reduction.

Keywords

Cite

@article{arxiv.2112.12452,
  title  = {Two disguises of the linear representation of a subgeometry},
  author = {Lins Denaux},
  journal= {arXiv preprint arXiv:2112.12452},
  year   = {2021}
}

Comments

9 pages, 2 figures