Hall's universal group is a subgroup of the abstract commensurator of a free group

• Published in: arXiv.org
• Main Authors: Bering, Edgar A, Studenmund, Daniel
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 12.11.2021
• Subjects: Group theory; Isomorphism; Subgroups

P. Hall constructed a universal countable locally finite group U, determined up to isomorphism by two properties: every finite group C is a subgroup of U, and every embedding of C into U is conjugate in U. Every countable locally finite group is a subgroup of U. We prove that U is a subgroup of the...