English

Abelian groups definable in $p$-adically closed fields

Logic 2022-08-23 v2

Abstract

Recall that a group GG has finitely satisfiable generics (fsgfsg) or definable ff-generics (dfgdfg) if there is a global type pp on GG and a small model M0M_0 such that every left translate of pp is finitely satisfiable in M0M_0 or definable over M0M_0, respectively. We show that any abelian group definable in a pp-adically closed field is an extension of a definably compact fsgfsg definable group by a dfgdfg definable group. We discuss an approach which might prove a similar statement for interpretable abelian groups. In the case where GG is an abelian group definable in the standard model Qp\mathbb{Q}_p, we show that G0=G00G^0 = G^{00}, and that GG is an open subgroup of an algebraic group, up to finite factors. This latter result can be seen as a rough classification of abelian definable groups in Qp\mathbb{Q}_p.

Keywords

Cite

@article{arxiv.2206.14364,
  title  = {Abelian groups definable in $p$-adically closed fields},
  author = {Will Johnson and Ningyuan Yao},
  journal= {arXiv preprint arXiv:2206.14364},
  year   = {2022}
}

Comments

20 pages; updated references and fixed subscript typo in abstract

R2 v1 2026-06-24T12:07:44.106Z