Sombor index of certain graphs

Let G = (V,E) be a finite simple graph. The Sombor index SO(G) of G is defined as ΣuvϵE(G)√ d^2 u + d^2v, where du is the degree of vertex u in G. In this paper, we study this index for certain graphs and we examine the effects on SO(G) when G is modified by operations on vertex and edge of G. Also we present bounds for the Sombor index of join and corona product of two graphs.