English

Fields and rings with few types

Logic 2019-03-01 v1

Abstract

Let R be an associative ring with possible extra structure. R is said to be weakly small if there are countably many 1-types over any finite subset of R. It is locally P if the algebraic closure of any finite subset of R has property P. It is shown here that a field extension of finite degree of a weakly small field either is a finite field or has no Artin-Schreier extension. A weakly small field of characteristic 2 is finite or algebraically closed. Every weakly small division ring of positive characteristic is locally finite dimensional over its centre. The Jacobson radical of a weakly small ring is locally nilpotent. Every weakly small division ring is locally, modulo its Jacobson radical, isomorphic to a product of finitely many matrix rings over division rings.

Keywords

Cite

@article{arxiv.1104.0288,
  title  = {Fields and rings with few types},
  author = {Cédric Milliet},
  journal= {arXiv preprint arXiv:1104.0288},
  year   = {2019}
}
R2 v1 2026-06-21T17:48:31.749Z