Characterization of intersecting families of maximum size in $PSL(2,q)$
Combinatorics
2020-01-30 v3
Abstract
We consider the action of the -dimensional projective special linear group on the projective line over the finite field , where is an odd prime power. A subset of is said to be an intersecting family if for any , there exists an element such that . It is known that the maximum size of an intersecting family in is . We prove that all intersecting families of maximum size are cosets of point stabilizers for all odd prime powers .
Keywords
Cite
@article{arxiv.1608.07304,
title = {Characterization of intersecting families of maximum size in $PSL(2,q)$},
author = {Ling Long and Rafael Plaza and Peter Sin and Qing Xiang},
journal= {arXiv preprint arXiv:1608.07304},
year = {2020}
}
Comments
32 pages, corrected some minor errors; in particular, stated the new Theorem 1 and 3 with the extra condition that $q>3$