English

Strongly bounded groups of various cardinalities

Group Theory 2020-10-07 v1

Abstract

Strongly bounded groups are those groups for which every action by isometries on a metric space has orbits of finite diameter. Many groups have been shown to have this property, and all the known infinite examples so far have cardinality at least 202^{\aleph_0}. We produce examples of strongly bounded groups of many cardinalities, including 1\aleph_1, answering a question of Yves de Cornulier [4]. In fact, any infinite group embeds as a subgroup of a strongly bounded group which is, at most, two cardinalities larger.

Keywords

Cite

@article{arxiv.1906.10481,
  title  = {Strongly bounded groups of various cardinalities},
  author = {Samuel M. Corson and Saharon Shelah},
  journal= {arXiv preprint arXiv:1906.10481},
  year   = {2020}
}
R2 v1 2026-06-23T10:02:59.213Z