Commensurations of the outer automorphism group of a universal Coxeter group

  • Yassine Guerch

    Université Paris-Saclay, Orsay, France
Commensurations of the outer automorphism group of a universal Coxeter group cover
Download PDF

This article is published open access under our Subscribe to Open model.

Abstract

This paper studies the rigidity properties of the abstract commensurator of the outer automorphism group of a universal Coxeter group of rank , which is the free product of copies of . We prove that for the natural map is an isomorphism and that every isomorphism between finite index subgroups of is given by a conjugation by an element of .

Cite this article

Yassine Guerch, Commensurations of the outer automorphism group of a universal Coxeter group. Groups Geom. Dyn. 17 (2023), no. 3, pp. 923–983

DOI 10.4171/GGD/718