English

Generic expansion of an abelian variety by a subgroup

Logic 2019-12-24 v1

Abstract

Let AA be an abelian variety in a field of characteristic 00. We prove that the expansion of AA by a generic divisible subgroup of AA with the same torsion exists provided AA has few algebraic endomorphisms, namely End(A)=Z\mathrm{End}(A)=\mathbb Z. The resulting theory is NSOP1\mathrm{NSOP}_1 and not simple. Note that there exist abelian varieties AA with End(A)=Z\mathrm{End}(A) = \mathbb{Z} of any genus. We indicate how this result can be extended to any simple abelian variety by considering the expansion by a predicate for some submodule over End(A)\mathrm{End}(A).

Keywords

Cite

@article{arxiv.1912.10911,
  title  = {Generic expansion of an abelian variety by a subgroup},
  author = {Christian d'Elbée},
  journal= {arXiv preprint arXiv:1912.10911},
  year   = {2019}
}

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8 pages