On abstract commensurators of groups - Mathematics > Group TheoryReport as inadecuate




On abstract commensurators of groups - Mathematics > Group Theory - Download this document for free, or read online. Document in PDF available to download.

Abstract: We prove that the abstract commensurator of a nonabelian free group, aninfinite surface group, or more generally of a group that splits appropriatelyover a cyclic subgroup, is not finitely generated.This applies in particular to all torsion-free word-hyperbolic groups withinfinite outer automorphism group and abelianization of rank at least 2.We also construct a finitely generated, torsion-free group which can bemapped onto Z and which has a finitely generated commensurator.



Author: Laurent Bartholdi, Oleg Bogopolski

Source: https://arxiv.org/



DOWNLOAD PDF




Related documents