English

Constructing abelian varieties from rank 2 Galois representations

Algebraic Geometry 2023-10-06 v3 Number Theory

Abstract

Let UU be a smooth affine curve over a number field KK with a compactification XX and let L\mathbb L be a rank 22, geometrically irreducible Qˉ\bar{\mathbb Q}_\ell-local system on UU with cyclotomic determinant that extends to an integral model, has Frobenius traces all in some fixed number field EQˉE\subset \bar{\mathbb Q}_\ell, and has bad, infinite reduction at some closed point xx of XUX\setminus U. We show that L\mathbb L occurs as a summand of the cohomology of a family of abelian varieties over UU. The argument follows the structure of the proof of a recent theorem of Snowden-Tsimerman, who show that when E=QE=\mathbb Q, then L\mathbb L is isomorphic to the cohomology of an elliptic curve EUUE_U\rightarrow U.

Keywords

Cite

@article{arxiv.2208.01999,
  title  = {Constructing abelian varieties from rank 2 Galois representations},
  author = {Raju Krishnamoorthy and Jinbang Yang and Kang Zuo},
  journal= {arXiv preprint arXiv:2208.01999},
  year   = {2023}
}

Comments

23 pages

R2 v1 2026-06-25T01:26:39.191Z