Fields of definition of elliptic k-curves and the realizability of all genus 2 Sato-Tate groups of over a number field

Let $ A/\mathbb{Q}$ be an abelian variety of dimension $ g\geq 1$ that is isogenous over $ \overline {\mathbb{Q}}$ to $ E^g$, where $ E$ is an elliptic curve. If $ E$ does not have complex multiplication (CM), by results of Ribet and Elkies concerning fields of definition of elliptic $ \mathbb{Q}$-c...

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Detalles Bibliográficos
Autores: Fité Naya, Francesc, Guitart Morales, Xavier
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/142922
Acceso en línea:https://hdl.handle.net/2445/142922
Access Level:acceso abierto
Palabra clave:Corbes el·líptiques
Teoria de grups
Elliptic curves
Group theory
Descripción
Sumario:Let $ A/\mathbb{Q}$ be an abelian variety of dimension $ g\geq 1$ that is isogenous over $ \overline {\mathbb{Q}}$ to $ E^g$, where $ E$ is an elliptic curve. If $ E$ does not have complex multiplication (CM), by results of Ribet and Elkies concerning fields of definition of elliptic $ \mathbb{Q}$-curves, $ E$ is isogenous to a curve defined over a polyquadratic extension of $ \mathbb{Q}$. We show that one can adapt Ribet's methods to study the field of definition of $ E$ up to isogeny also in the CM case. We find two applications of this analysis to the theory of Sato-Tate groups: First, we show that $ 18$ of the $ 34$ possible Sato-Tate groups of abelian surfaces over $ \mathbb{Q}$ occur among at most $ 51$ $ \overline {\mathbb{Q}}$-isogeny classes of abelian surfaces over $ \mathbb{Q}$. Second, we give a positive answer to a question of Serre concerning the existence of a number field over which abelian surfaces can be found realizing each of the $ 52$ possible Sato-Tate groups of abelian surfaces.