Publications
Sort:
Open Access Research Article Issue
On the sum of powers of the Aα-eigenvalues of graphs
Mathematical Modelling and Control 2022, 2(2): 55-64
Published: 15 June 2022
Abstract PDF (2.9 MB) Collect
Downloads:0

Let A(G) and D(G) be the adjacency matrix and the degree diagonal matrix of a graph G, respectively. For any real number α[0,1], Nikiforov recently defined the Aα-matrix of G as Aα(G)=αD(G)+(1α)A(G). The graph invariant Sαp(G) is the sum of the p-th power of the Aα-eigenvalues of G for 12<α<1, which has a close relation to the α-Estrada index. In this paper, we establish some bounds on Sαp(G) and characterize the extremal graphs. In particular, we present some bounds on Sαp(G) in terms of the degree sequences, order and size of G by using majorization techniques. Moreover, we give lower and upper bounds for Sαp(G) of a bipartite graph and characterize the extremal graphs.

Open Access Research Article Issue
Degree-weighted Wiener index of a graph
Mathematical Modelling and Control 2024, 4(1): 9-16
Published: 14 March 2024
Abstract PDF (2.9 MB) Collect
Downloads:58

From geometric point of view, we introduced the Sombor-Wiener index of a graph and studied the basic properties of the new index. It was shown that the Sombor-Wiener index was useful in predicting the acentric factor of octane isomers. In addition, we proposed a degree-weighted Wiener index to generalize the Schultz index, the Gutman index, and the Sombor-Wiener index. Meanwhile, we gave the calculation formula of degree-weighted Wiener index for generalized Bethe trees.

Total 2