Extremal values on the eccentric distance sum of trees

Abstract: Let G = (VG, EG) be a simple connected graph. The eccentric distance sum of G is defined as ξ(G) = ∑ v∈VG εG(v)DG(v), where εG(v) is the eccentricity of the vertex v and DG(v) = ∑ u∈VG dG(u, v) is the sum of all distances from the vertex v. In this paper the tree among n-vertex trees with domination number γ having the minimal eccentric distance sum is determined and the tree among n-vertex trees with domination number γ satisfying n = kγ having the maximal eccentric distance sum is identified, respectively, for k = 2, 3, n3 , n 2 . Sharp upper and lower bounds on the eccentric distance sums among the n-vertex trees with k leaves are determined. Finally, the trees among the n-vertex trees with a given bipartition having the minimal, second minimal and third minimal eccentric distance sums are determined, respectively.