English

Non-$\forall$-homogeneity in free groups

Logic 2020-01-28 v1 Group Theory

Abstract

We prove that non-abelian free groups of finite rank at least 3 or of countable rank are not \forall-homogeneous. We answer three open questions from Kharlampovich, Myasnikov, and Sklinos regarding whether free groups, finitely generated elementary free groups, and non-abelian limit groups form special kinds of Fra\"iss\'e classes in which embeddings must preserve \forall-formulas. We also provide interesting examples of countable non-finitely generated elementary free groups.

Keywords

Cite

@article{arxiv.2001.09904,
  title  = {Non-$\forall$-homogeneity in free groups},
  author = {Olga Kharlampovich and Christopher Natoli},
  journal= {arXiv preprint arXiv:2001.09904},
  year   = {2020}
}
R2 v1 2026-06-23T13:21:56.882Z