Sombor index and its applications

A novel topological index, the Sombor index, has been proposed by Ivan Gutman in a recent paper [1]. Motivated by this novel index, we study the new variants of Sombor index and to examine the correlation of newly introduced topological indices we have computed the values of these indices by taking all possible trees on 10 vertices. Here in this paper, we derive explicit formulae for the Sombor index of various nanostructures. These include hexagonal parallelogram \( P(\alpha, \beta) \)-nanotubes, triangular benzenoid \( G_{\alpha} \), and zigzag-edge coronoid fused with starphene nanotubes \( ZCS(k,\alpha,\beta) \), where \( k, \alpha, \beta \) are natural numbers. We also compute the Sombor index for dominating derived networks \( D_{1}, D_{2}, D_{3} \), as well as for various dendrimers such as Porphyrin Dendrimer, Ninc-Porphyrin Dendrimer, Propyl Ether Imine Dendrimers, and Polyamidoamin (PAMAM) Dendrimer. Additionally, we examine Polyamidoamin dendrimers (\( PD_{1}, PD_{2}, DS_{1} \)) and linear polyomino chains like \( L_{\alpha} \), \( Z_{\alpha} \), \( B^{1}_{\alpha}(\alpha \geq 3) \), \( B^{2}_{\alpha}(\alpha \geq 4) \). Finally, we consider benzenoid systems with different shapes, including triangular, hourglass, and jagged-rectangle configurations. By computing the Sombor index for these nanostructures, we provide a comprehensive analysis of their topological properties.