Publication:

On the variable inverse sum deg index

Several important topological indices studied in mathematical chemistry are expressed in the following way , where is a two variable function that satisfies the condition , denotes an edge of the graph and is the degree of the vertex . Among them, the variable inverse sum deg index , with , was found to have several applications. In this paper, we solve some problems posed by Vukičević [1], and we characterize graphs with maximum and minimum values of the index, for , in the following sets of graphs with vertices: graphs with fixed minimum degree, connected graphs with fixed minimum degree, graphs with fixed maximum degree, and connected graphs with fixed maximum degree. Also, we performed a QSPR analysis to test the predictive power of this index for some physicochemical properties of polyaromatic hydrocarbons.