English

Dp and other minimalities

Logic 2026-02-11 v3

Abstract

A first order expansion of (R,+,<)(\mathbb{R},+,<) is dp-minimal if and only if it is o-minimal. We prove analogous results for algebraic closures of finite fields, pp-adic fields, ordered abelian groups with only finitely many convex subgroups (in articular archimedean ordered abelian groups), and abelian groups equipped with archimedean cyclic group orders. The latter allows us to describe unary definable sets in dp-minimal expansions of (Z,+,C)(\mathbb{Z},+,C), where CC is a cyclic group order. Along the way we describe unary definable sets in dp-minimal expansions of ordered abelian groups. In the last section we give a canonical correspondence between dp-minimal expansions of (Q,+,<)(\mathbb{Q},+,<) and o-minimal expansions R\mathcal{R} of (R,+,<)(\mathbb{R},+,<) such that (R,Q)(\mathcal{R},\mathbb{Q}) is a "dense pair".

Keywords

Cite

@article{arxiv.1909.05399,
  title  = {Dp and other minimalities},
  author = {Pierre Simon and Erik Walsberg},
  journal= {arXiv preprint arXiv:1909.05399},
  year   = {2026}
}

Comments

The results on the p-adics are generalized to cover finite extensions of the p-adics and we added a p-adic analogue of the result on divisible archimedean ordered abelian groups

R2 v1 2026-06-23T11:12:57.158Z