English

Constructing Jacobians of rank 1

Number Theory 2025-09-30 v1

Abstract

Let KK be a number field, let g1g \geq 1 be an integer and let f(x)=(xa1)(xa2g+1)OK[x]f(x) = (x - a_1) \cdots (x - a_{2g + 1}) \in O_K[x] be a polynomial that splits into 2g+12g + 1 distinct linear factors. Write CC for the hyperelliptic curve given by C:y2=f(x)C: y^2 = f(x) and write J=Jac(C)J = \mathrm{Jac}(C) for its Jacobian. Under mild technical assumptions on ff that are satisfied almost always, we prove that there exists some dK×d \in K^\times such that the quadratic twist JdJ^d has rank exactly equal to 11. As a consequence, we deduce that for any positive integer gg, there exists an absolutely simple abelian variety over KK with dimension equal to gg and rank equal to 11.

Keywords

Cite

@article{arxiv.2509.24937,
  title  = {Constructing Jacobians of rank 1},
  author = {Peter Koymans and Adam Morgan},
  journal= {arXiv preprint arXiv:2509.24937},
  year   = {2025}
}
R2 v1 2026-07-01T06:04:51.595Z