On the clique number of the square of a line graph and its relation to maximum degree of the line graph
Abstract
In 1985, Erdős and Nešetřil conjectured that the square of the line graph of a graph , that is,
, can be colored with
colors. This conjecture implies the weaker conjecture that the clique number of such a graph, that is,
, is at most
. In 2015, Śleszyńska-Nowak proved that
. In this paper, we prove that
. This theorem follows from our stronger result that
where
.