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arXiv · 1012.4127

Abstract commensurators of solvable Baumslag - Solitar groups

Oleg Bogopolski
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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.

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Oleg Bogopolski. 2010-12-18. Abstract commensurators of solvable Baumslag - Solitar groups. https://arxiv.org/abs/1012.4127

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