Distance Critical Graphs
摘要
In 1971, Graham and Pollak provided a formula for the determinant of the distance matrix of any tree on n vertices. Yan and Yeh reproved this by exploiting the fact that pendant vertices can be deleted from trees without changing the remaining entries of the distance matrix. Considering failures of their argument to generalize invites the question: which graphs have the property that deleting any one vertex results in a change to some pairwise distance? Such worst-case graphs are known as “distance critical”, and were first studied by Erdős and Howorka. This work explores the structural properties of distance critical graphs, preservation of distance-criticality by products, and the nature of extremal distance critical graphs. We end with a few open questions.