English

Extremal values on the eccentric distance sum of trees

Combinatorics 2012-07-03 v1

Abstract

Let G=(VG,EG)G=(V_G, E_G) be a simple connected graph. The eccentric distance sum of GG is defined as ξd(G)=vVGεG(v)DG(v)\xi^{d}(G) = \sum_{v\in V_G}\varepsilon_{G}(v)D_{G}(v), where εG(v)\varepsilon_G(v) is the eccentricity of the vertex vv and DG(v)=uVGdG(u,v)D_G(v) = \sum_{u\in V_G}d_G(u,v) is the sum of all distances from the vertex vv. In this paper the tree among nn-vertex trees with domination number γ\gamma having the minimal eccentric distance sum is determined and the tree among nn-vertex trees with domination number γ\gamma satisfying n=kγn = k\gamma having the maximal eccentric distance sum is identified, respectively, for k=2,3,n3,n2k=2,3,\frac{n}{3},\frac{n}{2}. Sharp upper and lower bounds on the eccentric distance sums among the nn-vertex trees with kk leaves are determined. Finally, the trees among the nn-vertex trees with a given bipartition having the minimal, second minimal and third minimal eccentric distance sums are determined, respectively.

Keywords

Cite

@article{arxiv.1207.0083,
  title  = {Extremal values on the eccentric distance sum of trees},
  author = {Shuchao Li and Meng Zhang},
  journal= {arXiv preprint arXiv:1207.0083},
  year   = {2012}
}

Comments

15 Pages, 8 figures