  Recently, Gutman [MATCH Commun. Math. Comput. Chem. 86 (2021) 11-16] defined
a new graph invariant which is named the Sombor index $\mathrm{SO}(G)$ of a
graph $G$ and is computed via the expression \[
  \mathrm{SO}(G) = \sum_{u \sim v} \sqrt{\mathrm{deg}(u)^2 + \mathrm{deg}(v)^2}
, \] where $\mathrm{deg}(u)$ represents the degree of the vertex $u$ in $G$ and
the summing is performed across all the unordered pairs of adjacent vertices
$u$ and $v$. Here we take into consideration the set of all the trees
$\mathcal{T}_D$ that have a specified degree sequence $D$ and show that the
greedy tree attains the minimum Sombor index on the set $\mathcal{T}_D$.
