2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/167860Let $K$ be a totally real number field with Galois closure $L$. We prove that if $f \in \mathbb Q[x_1,...,x_n]$ is a sum of $m$ squares in $K[x_1,...,x_n]$, then $f$ is a sum of \[4m \cdot 2^{[L: \mathbb Q]+1} {[L: \mathbb Q] +1 \choose 2}\] squares in $\mathbb Q[x_1,...,x_n]$. Moreover, our argument is constructive and generalizes to the case of commutative $K$-algebras. This result gives a partial resolution to a question of Sturmfels on the algebraic degree of certain semidefinite programing problems.10 pages, final version to appear in Proceedings of the AMSCommutative AlgebraOptimization and ControlRings and AlgebrasSums of squares over totally real fields are rational sums of squarestext