Given an arbitrary connected graph G, the n-polygon τn(G) is obtained by adding a path with length n (n≥2) to each edge of and iterated graphs τng(G) (g≥0) are from iteration τng(G)=τn(τng−1(G)), initial condition τn0(G)=G. In this paper, method for calculating eigenvalues normalized Laplacian matrix presented if G first given. The spectra can also then be derived. Finally, as applications, we ...

the total version of geometric–arithmetic index of graphs is introduced based on the endvertexdegrees of edges of their total graphs. in this paper, beside of computing the total gaindex for some graphs, its some properties especially lower and upper bounds are obtained.

For a simple connected graph G of order n, having Laplacian eigenvalues μ1, μ2, . . . , μn−1, μn = 0, the Laplacian–energy–like invariant (LEL) and the Kirchhoff index (Kf) are defined as LEL(G) = ∑n−1 i=1 √ μi and Kf(G) = n ∑n−1 i=1 1 μi , respectively. In this paper, LEL and Kf are compared, and sufficient conditions for the inequality Kf(G) < LEL(G) are established.

We define a subdivision network Γ of a given network Γ, by inserting a new vertex in every edge, so that each edge is replaced by two new edges with conductances that fulfill electrical conditions on the new network. In this work, we firstly obtain an expression for the Green kernel of the subdivision network in terms of the Green kernel of the base network. Moreover, we also obtain the effecti...

We introduce a procedure, called the Degree Sequence Index Strategy (DSI), by which to bound graph invariants by certain indices in the ordered degree sequence. As an illustration of the DSI strategy, we show how it can be used to give new upper and lower bounds on the k-independence and the k-domination numbers. These include, among other things, a double generalization of the annihilation num...

The k-th semi-total point graph R(G) of a graph G, is a graph obtained from G by adding k vertices corresponding to each edge and connecting them to the endpoints of the edge considered. In this paper, we obtain formulas for the resistance distance and Kirchhoff index of R(G).