The Square Sieve and a Lang-Trotter Question for Generic Abelian Varieties

Abstract

Let $A$ be a $g$-dimensional abelian variety over $\mathbb{Q}$ whose adelic Galois representation has open image in ${\text{GSp}}_{2g}\hat{\mathbb{Z}}$. We investigate the endomorphism algebras $\text{End}(A_p)\otimes \mathbb{Q}=\mathbb{Q}({\pi }_p)$ of the reduction of $A$ modulo primes $p$ at which this reduction is ordinary and simple. We obtain conditional and unconditional asymptotic upper bounds on the number of primes at which this "Frobenius field" is a specified number field and, when $A$ is two-dimensional, at which the Frobenius field contains a specified real quadratic number field. These investigations continue the investigations of variants of the Lang-Trotter Conjectures on elliptic curves.

Fixed typos and citations; added experimental datum. 28 pages; abstract slightly modified for metadata. Comments welcome!

References in corpus (1)

• An open image theorem for a general class of abelian varieties