The Sombor Index of Trees and Unicyclic Graphs with Given Maximum Degree

Let $d_G(v)$ be the degree of vertex $v$ in a graph $G$. The Sombor index $G$ is defined as $SO(G) =\sum_{uv\in E(G)}\sqrt{d^2_G(u)+d^2_G(v)}$, which new degree-based topological introduced by Gutman. $\mathscr{T}_{n,\Delta}$ and $\mathscr{U}_{n,\Delta}$ set trees unicyclic graphs with $n$ vertices maximum $\Delta$, respectively. In this paper, tree minimum among are characterized.