نتایج جستجو برای: first zagreb index

تعداد نتایج: 1785322  

2017
Hamideh Aram Nasrin Dehgardi

The first general Zagreb index is defined as Mλ 1 (G) = ∑ v∈V (G) dG(v) λ where λ ∈ R − {0, 1}. The case λ = 3, is called F-index. Similarly, reformulated first general Zagreb index is defined in terms of edge-drees as EMλ 1 (G) = ∑ e∈E(G) dG(e) λ and the reformulated F-index is RF (G) = ∑ e∈E(G) dG(e) 3. In this paper, we compute the reformulated F-index for some graph operations.

Journal: :Discrete Dynamics in Nature and Society 2020

Journal: :Discrete Applied Mathematics 2022

In this paper we study lower bounds in a unified way for large family of topological indices, including the first variable Zagreb index M 1 ? . Our aim is to obtain sharp inequalities and characterize corresponding extremal graphs. The main results provide several vertex-degree-based indices. These are new even Zagreb, inverse forgotten

2010
Qin Zhao Shuchao Li

For a (molecular) graph, the first Zagreb index M1 is equal to the sum of squares of the vertex degrees, and the second Zagreb index M2 is equal to the sum of products of degrees of pairs of adjacent vertices. In this paper, we study the Zagreb indices of n-vertex connected graphs with k cut vertices, the upper bound for M1and M2-values of n-vertex connected graphs with k cut vertices are deter...

A. IRANMANESH I. GUTMAN M. HOSSEINZADEH

Todeschini et al. have recently suggested to consider multiplicative variants of additive graph invariants, which applied to the Zagreb indices would lead to the multiplicative Zagreb indices of a graph G, denoted by ( ) 1  G and ( ) 2  G , under the name first and second multiplicative Zagreb index, respectively. These are define as     ( ) 2 1 ( ) ( ) v V G G G d v and ( ) ( ) ( ) ( ) 2...

Journal: :Australasian J. Combinatorics 2010
Muhuo Liu Bolian Liu

In this paper, the effects on the first general Zagreb index are observed when some operations, such as edge moving, edge separating and edge switching are applied to the graphs. Moreover, we obtain the majorization theorem to the first general Zagreb indices between two graphic sequences. Furthermore, we illustrate the application of these new properties, and obtain the largest or smallest fir...

2012
Kexiang Xu Kinkar Ch. Das

For a (molecular) graph G with vertex set V (G) and edge set E(G), the first Zagreb index of G is defined as M1(G) = ∑ v∈V (G) dG(v) 2 where dG(v) is the degree of vertex v in G. The alternative expression for M1(G) is ∑ uv∈E(G)(dG(u)+dG(v)). Very recently, Eliasi, Iranmanesh and Gutman [7] introduced a new graphical invariant ∏∗ 1(G) = ∏ uv∈E(G)(dG(u) + dG(v)) as the multiplicative version of ...

Journal: :international journal of industrial mathematics 0
v. ahmadi department of mathematics, tehran university, tehran, ‎iran. m. r. ‎darafsheh department of mathematics, shahid chamran university, ahvaz, ‎iran‎. j. ‎hashemi‎ department of mathematics, tehran university, tehran, ‎iran.

‎let g=(v,e) be a simple connected graph with vertex set v and edge set e. the first, second and third zagreb indices of g are respectivly defined by: $m_1(g)=sum_{uin v} d(u)^2, hspace {.1 cm} m_2(g)=sum_{uvin e} d(u).d(v)$ and $ m_3(g)=sum_{uvin e}| d(u)-d(v)| $ , where d(u) is the degree of vertex u in g and uv is an edge of g connecting the vertices u and v. recently, the first and second m...

Journal: :Axioms 2023

The first entire Zagreb index (FEZI) is a graph parameter that has proven to be essential in various real-life scenarios, such as networking businesses and traffic management on roads. In this research paper, the FEZI was explored for variety of fuzzy graphs, including star, firefly graph, cycle, path, subgraph, vertex elimination, edge elimination. This study presented several results, determi...

Journal: :iranian journal of mathematical chemistry 2011
z. yarahmadi

a topological index of a molecular graph g is a numeric quantity related to g which isinvariant under symmetry properties of g. in this paper we obtain the randić, geometricarithmetic,first and second zagreb indices , first and second zagreb coindices of tensorproduct of two graphs and then the harary, schultz and modified schultz indices of tensorproduct of a graph g with complete graph of ord...

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