English

On countable isotypic structures

Logic 2025-06-18 v4

Abstract

We obtain several results concerning the concept of isotypic structures. Namely we prove that any field of finite transcendence degree over a prime subfield is defined by types; then we construct isotypic but not isomorphic structures with countable underlying sets: totally ordered sets, fields, and groups. This answers an old question by B. Plotkin for groups.

Keywords

Cite

@article{arxiv.2308.10812,
  title  = {On countable isotypic structures},
  author = {Pavel Gvozdevsky},
  journal= {arXiv preprint arXiv:2308.10812},
  year   = {2025}
}

Comments

6 pages, Published in journal of Groups, Complexity, Cryptology