Total eccentricity index of graphs with fixed number of pendant or cut vertices

Abstract

The total eccentricity index of a connected graph is defined as sum of the eccentricities of all its vertices. In this paper, we give the sharp upper bound on the total eccentricity index over graphs with fixed number of pendant vertices and the sharp lower bound on the same over graphs with fixed number of cut vertices. We also provide the sharp upper bounds on the total eccentricity index over graphs with s cut vertices for \(s=0, 1, n-3, n-2\) and propose a conjecture for \(2\le s\le n-4\).