Azarbaijan Shahid Madani University Communications in Combinatorics and Optimization 2538-2128 11 3 2026 09 01 Extremal trees for the general Sombor index 911 922 14866 10.22049/cco.2024.29444.1996 EN Chinglensana Phanjoubam Department of Mathematics, North-Eastern Hill University, Shillong, India Sainkupar Mn Mawiong Department of Basic Sciences and Social Sciences, North-Eastern Hill University, Shillong, India Ardeline M. Buhphang Department of Mathematics, North-Eastern Hill University, Shillong, India Journal Article 2024 02 11 Recently, the Sombor index of a graph has been extended to general Sombor index. The general Sombor index of a simple graph $G$ is defined as $SO_\alpha(G)=\displaystyle\sum_{uv\in E(G)}[d_G(u)^2+d_G(v)^2]^{{\alpha}/2}$, where $d_G(u)$ denotes the degree of a vertex $u$ in $G$ and $\alpha$ is a real number. In this paper, we obtain bounds for the general Sombor index of trees. We further determine the trees with the extremal general Sombor indices. https://comb-opt.azaruniv.ac.ir/article_14866_a0357e603986d2b1c3924744c5da59fd.pdf