Computer Algebra
《Computer Algebra》 · 第 50 页 · Section 10「Endomorphisms」，Remark 10.17
Suppose that $k$ is finitely generated over its prime field, let $\Gamma=\operatorname{Gal}(k^{\mathrm{al}}/k)$, and let $A$ and $B$ be abelian varieties over $k$. In 1964, Tate conjectured that $\operatorname{Hom}(A,B)\otimes\mathbb Z_\ell\to\operatorname{Hom}(T_\ell A,T_\ell B)^\Gamma$ is an isomorphism, where the superscript means the $\mathbb Z_\ell$-linear homomorphisms commuting with the action of $\Gamma$.