English

Stable groups and expansions of $(\mathbb{Z},+,0)$

Logic 2018-09-12 v3

Abstract

We show that if GG is a sufficiently saturated stable group of finite weight with no infinite, infinite-index, chains of definable subgroups, then GG is superstable of finite UU-rank. Combined with recent work of Palacin and Sklinos, we conclude that (Z,+,0)(\mathbb{Z},+,0) has no proper stable expansions of finite weight. A corollary of this result is that if PZnP\subseteq\mathbb{Z}^n is definable in a finite dp-rank expansion of (Z,+,0)(\mathbb{Z},+,0), and (Z,+,0,P)(\mathbb{Z},+,0,P) is stable, then PP is definable in (Z,+,0)(\mathbb{Z},+,0). In particular, this answers a question of Marker on stable expansions of the group of integers by sets definable in Presburger arithmetic.

Keywords

Cite

@article{arxiv.1601.05692,
  title  = {Stable groups and expansions of $(\mathbb{Z},+,0)$},
  author = {Gabriel Conant and Anand Pillay},
  journal= {arXiv preprint arXiv:1601.05692},
  year   = {2018}
}

Comments

10 pages, final version to appear in Fundamenta Mathematicae