English

Abstract commensurators of solvable Baumslag - Solitar groups

Group Theory 2011-03-04 v2

Abstract

We prove that for any natural n>1, the abstract commensurator group of the Baumslag - Solitar group BS(1,n) is isomorphic to the group of 2 by 2 upper triangular matrices A over rational numbers with A_{11}=1. We also prove that for any finitely generated group G with the unique root property the natural homomorphisms Aut(G)--> Comm(G)--> QI(G) are embeddings.

Keywords

Cite

@article{arxiv.1012.4127,
  title  = {Abstract commensurators of solvable Baumslag - Solitar groups},
  author = {Oleg Bogopolski},
  journal= {arXiv preprint arXiv:1012.4127},
  year   = {2011}
}

Comments

8 pages, no figure