University of KashanIranian Journal of Mathematical Chemistry2228-648912120210301Sombor index of certain graphs273711134510.22052/ijmc.2021.242106.1547ENNima GhanbariDepartment of Informatics, University of Bergen, P.O. Box 7803, 5020 Bergen, Norway0000-0001-5063-3461Saeid AlikhaniDepartment of Mathematics, Yazd University, 89195-741, Yazd, Iran0000-0002-1801-203XJournal Article20210227Let $G=(V,E)$ be a finite simple graph. The Sombor index $SO(G)$ of $G$ is defined as $\sum_{uv\in E(G)}\sqrt{d_u^2+d_v^2}$, where $d_u$ 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.https://ijmc.kashanu.ac.ir/article_111345_ed933628a644aa468302d40b4b473edd.pdf