English

On the existence of abelian surfaces with everywhere good reduction

Number Theory 2019-03-26 v1

Abstract

Let D2000D \le 2000 be a positive discriminant such that F=Q(D)F = \mathbf{Q}(\sqrt{D}) has narrow class one, and A/FA/F an abelian surface of GL2{\rm GL}_2-type with everywhere good reduction. Assuming that AA is modular, we show that AA is either an FF-surface or is a base change from Q\mathbf{Q} of an abelian surface BB such that EndQ(B)=Z{\rm End}_{\mathbf{Q}}(B) = \mathbf{Z}, except for D=353,421,1321,1597D = 353, 421, 1321, 1597 and 19971997. In the latter case, we show that there are indeed abelian surfaces with everywhere good reduction over FF for D=353,421D = 353, 421 and 15971597, which are non-isogenous to their Galois conjugates. These are the first known such examples.

Keywords

Cite

@article{arxiv.1903.10394,
  title  = {On the existence of abelian surfaces with everywhere good reduction},
  author = {Lassina Dembele},
  journal= {arXiv preprint arXiv:1903.10394},
  year   = {2019}
}

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