The intersection graph of a finite simple group has diameter at most 5
arXiv:2009.02884 · doi:10.1007/s00013-021-01583-3
Abstract
Let be a non-abelian finite simple group. In addition, let be the intersection graph of , whose vertices are the proper nontrivial subgroups of , with distinct subgroups joined by an edge if and only if they intersect nontrivially. We prove that the diameter of has a tight upper bound of 5, thereby resolving a question posed by Shen (2010). Furthermore, a diameter of 5 is achieved only by the baby monster group and certain unitary groups of odd prime dimension.
8 pages. Corrected minor non-mathematical typos