English

On regular groups and fields

Logic 2012-11-19 v1 Group Theory

Abstract

Regular groups and fields are common generalizations of minimal and quasi-minimal groups and fields, so the conjectures that minimal or quasi-minimal fields are algebraically closed have their common generalization to the conjecture that each regular field is algebraically closed. Standard arguments show that a generically stable regular field is algebraically closed. Let KK be a regular field which is not generically stable and let pp be its global generic type. We observe that if KK has a finite extension LL of degree nn, then p(n)p^{(n)} has unbounded orbit under the action of the multiplicative group of LL. Known to be true in the minimal context, it remains wide open whether regular, or even quasi-minimal, groups are abelian. We show that if it is not the case, then there is a counter-example with a unique non-trivial conjugacy class, and we notice that a classical group with one non-trivial conjugacy class is not quasi-minimal, because the centralizers of all elements are uncountable. Then we construct a group of cardinality ω1\omega_1 with only one non-trivial conjugacy class and such that the centralizers of all non-trivial elements are countable.

Keywords

Cite

@article{arxiv.1211.3852,
  title  = {On regular groups and fields},
  author = {Tomasz Gogacz and Krzysztof Krupinski},
  journal= {arXiv preprint arXiv:1211.3852},
  year   = {2012}
}
R2 v1 2026-06-21T22:39:29.867Z