Title
The minimum value of geometric-arithmetic index of graphs with minimum degree 2.
Abstract
The geometric-arithmetic index was introduced in the chemical graph theory and it has shown to be applicable. The aim of this paper is to obtain the extremal graphs with respect to the geometric-arithmetic index among all graphs with minimum degree 2. Let G(2, n) be the set of connected simple graphs on n vertices with minimum degree 2. We use linear programming formulation and prove that the minimum value of the first geometric-arithmetic $$(GA_{1})$$(GA1) index of G(2, n) is obtained by the following formula: $$\\begin{aligned} GA_1^* = \\left\\{ \\begin{array}{ll} n&{}\\quad n \\le 24, \\\\ \\mathrm{{24}}\\mathrm{{.79}}&{}\\quad n = 25, \\\\ \\frac{{4\\left( {n - 2} \\right) \\sqrt{2\\left( {n - 2} \\right) } }}{n}&{}\\quad n \\ge 26. \\\\ \\end{array} \\right. \\end{aligned}$$GA1ź=nn≤24,24.79n=25,4n-22n-2nnź26.
Year
DOI
Venue
2017
10.1007/s10878-016-0062-4
J. Comb. Optim.
Keywords
Field
DocType
Geometric-arithmetic index,Extremal graphs,Linear programming
Chemical graph theory,Graph,Discrete mathematics,Linear programming formulation,Combinatorics,Mathematical optimization,Vertex (geometry),Linear programming,Mathematics
Journal
Volume
Issue
ISSN
34
1
1382-6905
Citations 
PageRank 
References 
1
0.40
4
Authors
2
Name
Order
Citations
PageRank
Mahdi Sohrabi-Haghighat110.40
Mohammadreza Rostami210.73