We construct an infinite family of intriguing sets, or equivalently perfect 2-colorings, that are not tight in the Grassmann graph of planes of PG$(n,q)$, $n\ge 5$ odd, and show that the members of the family are the smallest possible examples if $n\ge 9$ or $q\ge 25$.
@article{10_37236_8672,
author = {Stefaan De Winter and Klaus Metsch},
title = {Perfect 2-colorings of the {Grassmann} graph of planes},
journal = {The electronic journal of combinatorics},
year = {2020},
volume = {27},
number = {1},
doi = {10.37236/8672},
zbl = {1431.05065},
url = {http://geodesic.mathdoc.fr/articles/10.37236/8672/}
}
TY - JOUR
AU - Stefaan De Winter
AU - Klaus Metsch
TI - Perfect 2-colorings of the Grassmann graph of planes
JO - The electronic journal of combinatorics
PY - 2020
VL - 27
IS - 1
UR - http://geodesic.mathdoc.fr/articles/10.37236/8672/
DO - 10.37236/8672
ID - 10_37236_8672
ER -
%0 Journal Article
%A Stefaan De Winter
%A Klaus Metsch
%T Perfect 2-colorings of the Grassmann graph of planes
%J The electronic journal of combinatorics
%D 2020
%V 27
%N 1
%U http://geodesic.mathdoc.fr/articles/10.37236/8672/
%R 10.37236/8672
%F 10_37236_8672
Stefaan De Winter; Klaus Metsch. Perfect 2-colorings of the Grassmann graph of planes. The electronic journal of combinatorics, Tome 27 (2020) no. 1. doi: 10.37236/8672
