The distance matrices of some graphs related to wheel graphs

Let d denote the distance matrix of a connected graph g. the inertia of d is the triple of integers (n + (d),n 0 (d),n - (d)),where n + (d),n 0 (d),and n - (d) denote the number of positive,0,and negative eigenvalues of d,respectively. in this paper,we mainly study the inertia of distance matrices of some graphs related to wheel graphs and give a construction for graphs whose distance matrices have exactly one positive eigenvalue. © 2013 xiaoling zhang and chengyuan song.