New methods for calculating the degree distance and the Gutman index

Simon Brezovnik; Niko Tratnik

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arXiv · 1809.02358

New methods for calculating the degree distance and the Gutman index

Simon Brezovnik·Niko Tratnik

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Abstract

In the paper we develop new methods for calculating the two well-known topological indices, the degree-distance and the Gutman index. Firstly, we prove that the Wiener index of a double vertex-weighted graph can be computed from the Wiener indices of weighted quotient graphs with respect to a partition of the edge set that is coarser than $Θ^*$-partition. This result immediately gives a method for computing the degree-distance of any graph. Next, we express the degree-distance and the Gutman index of an arbitrary phenylene by using its hexagonal squeeze and inner dual. In addition, it is shown how these two indices of a phenylene can be obtained from the four quotient trees. Furthermore, reduction theorems for the Wiener index of a double vertex-weighted graph are presented. Finally, a formula for computing the Gutman index of a partial Hamming graph is obtained.

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Simon Brezovnik, Niko Tratnik. 2018-09-07. New methods for calculating the degree distance and the Gutman index. https://arxiv.org/abs/1809.02358

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