Fontaine–Mazur–Petrov conjecture for ℓ-adic local systems
Establish that an irreducible ℓ-adic local system \mathbb{V} on X_{K^s} is of geometric origin if and only if its isomorphism class has finite orbit under \operatorname{Gal}(K^s/K).
References
Conjecture [Fontaine-Mazur-Petrov\,{[Conjecture 1 bis]{petrov2023geometrically}] Let $\mathbb{V}$ be an irreducible $\ell$-adic local system on $X_{Ks}$. Then $\mathbb{V}$ is of geometric origin if and only if it its isomorphism class has finite orbit under $\on{Gal}(Ks/K)$.
— Motives, mapping class groups, and monodromy
(2409.02234 - Litt, 3 Sep 2024) in Conjecture (Fontaine–Mazur–Petrov), Section 5.1, Example: The Tate conjecture