Extremal values on the modified Sombor index of trees and unicyclic graphs

Let $G=(V,E)$ be a simple connected graph. The modified Sombor index denoted by $mSo(G)$ is defined as
$$mSo(G)=\sum_{uv\in E}\frac{1}{\sqrt{d^2_u+d^2_v}},$$
where $d_v$ denotes the degree of vertex $v$. In this paper we present extremal values of modified Sombor index over the set of trees and unicyclic graphs.