On the PSU(4, 2)-invariant vertex-transitive strongly regular (216, 40, 4, 8) graph
Combinatorics
2019-07-31 v1
Abstract
In 2018 the first, Rukavina and the third author constructed with the aid of a computer the first example of a strongly regular graph with parameters (216, 40, 4, 8) and proved that it is the unique PSU(4,2)-invariant vertex-transitive graph on 216 vertices. In this paper, using the geometry of the Hermitian surface of PG(3, 4), we provide a computer-free proof of the existence of the graph . The maximal cliques of are also determined.
Keywords
Cite
@article{arxiv.1907.12773,
title = {On the PSU(4, 2)-invariant vertex-transitive strongly regular (216, 40, 4, 8) graph},
author = {Dean Crnković and Francesco Pavese and Andrea Švob},
journal= {arXiv preprint arXiv:1907.12773},
year = {2019}
}