The weight $w$ of the Sato-Tate group $G$ of a motive $X$ is determined by the cohomology group $H^w(X,\mathbb{Q}_\ell)$ used to define $G$. The roots of the characteristic polynomials of Frobenius are then $q$-weil numbers $\alpha$ of weight $w$, meaning that $|\iota(\alpha)|=q^w/2$ for every embedding $\iota\colon \mathbb{Q}(\alpha)\to \mathbb{C}$.

**Authors:**