Graph robustness or network is the ability that a graph preserves its connectivity other properties after loss of vertices and edges, which has been central problem in research complex networks. In this paper, we introduce Modified Zagreb index centrality as novel measures to study robustness. We theoretically find some relationships between these measures. Then, use analyze BA scale-free netwo...

Albertson [3] has defined the irregularity of a simple undirected graph G = (V,E) as irr(G) = ∑ uv∈E |dG(u)− dG(v)| , where dG(u) denotes the degree of a vertex u ∈ V . Recently, this graph invariant gained interest in the chemical graph theory, where it occured in some bounds on the first and the second Zagreb index, and was named the third Zagreb index [13]. For general graphs with n vertices...

In this article, we investigate the Zagreb index, a kind of graph-based topological several random networks, including class networks extended from recursive trees, plain-oriented and caterpillars growing in preferential attachment manner. We calculate mean variance index for each class. addition, prove that asymptotic distribution first is normal, second skewed to right.

The concept of arithmetic-geometric index was recently introduced in chemical graph theory, but it has proven to be useful from both a theoretical and practical point view. aim this paper is obtain new bounds the characterize extremal graphs with respect them. Several are based on other indices, such as second variable Zagreb or general atom-bond connectivity index), some them involve parameter...