نتایج جستجو برای: First general Zagreb index

تعداد نتایج: 2354171  

The first general Zagreb index is defined as $M_1^lambda(G)=sum_{vin V(G)}d_{G}(v)^lambda$. The case $lambda=3$, is called F-index. Similarly, reformulated first general Zagreb index is defined in terms of edge-drees as $EM_1^lambda(G)=sum_{ein E(G)}d_{G}(e)^lambda$ and the reformulated F-index is $RF(G)=sum_{ein E(G)}d_{G}(e)^3$. In this paper, we compute the reformulated F-index for some grap...

Journal: :iranian journal of mathematical chemistry 2011
g. su l. xu

in this paper, a new molecular-structure descriptor, the general sum–connectivity co–index  is considered, which generalizes the first zagreb co–index and the general sum–connectivity index of graph theory. we mainly explore the lower and upper bounds in termsof the order and size for this new invariant. additionally, the nordhaus–gaddum–type resultis also represented.

Journal: :iranian journal of mathematical chemistry 0
r. rasi azarbaijan shahid madani university, tabriz, iran s. m. sheikholeslami azarbaijan shahid madani university, tabriz, iran a. behmaram institute for research in fundamental sciences, tehran, iran

in this paper we give sharp upper bounds on the zagreb indices and characterize all trees achieving equality in these bounds. also, we give lower bound on first zagreb coindex of trees.

Journal: :transactions on combinatorics 2015
ivan gutman muhammad kamran jamil naveed akhter

the first zagreb index $m_1$ of a graph $g$ is equal to the sum of squaresof degrees of the vertices of $g$. goubko proved that for trees with $n_1$pendent vertices, $m_1 geq 9,n_1-16$. we show how this result can beextended to hold for any connected graph with cyclomatic number $gamma geq 0$.in addition, graphs with $n$ vertices, $n_1$ pendent vertices, cyclomaticnumber $gamma$, and minimal $m...

Journal: :transactions on combinatorics 2016
nader habibi tayebeh dehghan zadeh ali reza ashrafi

the first zagreb index, $m_1(g)$, and second zagreb index, $m_2(g)$, of the graph $g$ is defined as $m_{1}(g)=sum_{vin v(g)}d^{2}(v)$ and $m_{2}(g)=sum_{e=uvin e(g)}d(u)d(v),$ where $d(u)$ denotes the degree of vertex $u$. in this paper, the firstand second maximum values of the first and second zagreb indicesin the class of all $n-$vertex tetracyclic graphs are presented.

Journal: :Discrete Dynamics in Nature and Society 2020

Inspired by the chemical applications of higher-order connectivity index (or Randic index), we consider here the higher-order first Zagreb index of a molecular graph. In this paper, we study the linear regression analysis of the second order first Zagreb index with the entropy and acentric factor of an octane isomers. The linear model, based on the second order first Zag...

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...

Journal: :Universal journal of mathematics and applications 2021

The first general Zagreb index of a graph $G$ is defined as the sum $\alpha$th powers vertex degrees $G$, where $\alpha$ real number such that $\alpha \neq 0$ and 1$. In this note, for > 1$, we present upper bounds involving chromatic clique numbers graph; an integer \geq 2$, lower bound independence graph.

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