English

Steep uncountable groups

Group Theory 2024-03-06 v1 Logic

Abstract

We produce a simple group GG of cardinality 1\aleph_1 which is Artinian (every strictly descending chain of subgroups is finite), satisfies a Burnside law and such that for each uncountable subset YGY \subseteq G there exists a natural number nYn_Y for which every element of GG may be expressed as a product of length at most nYn_Y of elements in Y±1Y^{\pm 1}. In particular this group is J\'onsson (every proper subgroup is of strictly smaller cardinality) and strongly bounded (every abstract action on a metric space has bounded orbits); this is the first example of an uncountable group having both of these properties which is constructed without using the continuum hypothesis. The group GG can also be made so that all subgroups are simple and all nontrivial subgroups are malnormal in GG.

Keywords

Cite

@article{arxiv.2305.02953,
  title  = {Steep uncountable groups},
  author = {Samuel M. Corson and Alexander Olshanskii and Olga Varghese},
  journal= {arXiv preprint arXiv:2305.02953},
  year   = {2024}
}