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Commensurating HNN-extensions: non-positive curvature and biautomaticity

Commensurating HNN-extensions: non-positive curvature and biautomaticity
Commensurating HNN-extensions: non-positive curvature and biautomaticity
We show that the commensurator of any quasiconvex abelian subgroup in a biautomatic group is small, in the sense that it has finite image in the abstract commensurator of the subgroup. Using this criterion we exhibit groups that are CAT(0) but not biautomatic. These groups also resolve a number of other questions concerning CAT(0) groups.
1465-3060
1819–1860
Leary, Ian
57bd5c53-cd99-41f9-b02a-4a512d45150e
Minasyan, Ashot
3de640f5-d07b-461f-b130-5b1270bfdb3d
Leary, Ian
57bd5c53-cd99-41f9-b02a-4a512d45150e
Minasyan, Ashot
3de640f5-d07b-461f-b130-5b1270bfdb3d

Leary, Ian and Minasyan, Ashot (2021) Commensurating HNN-extensions: non-positive curvature and biautomaticity. Geometry & Topology, 25 (4), 1819–1860.

Record type: Article

Abstract

We show that the commensurator of any quasiconvex abelian subgroup in a biautomatic group is small, in the sense that it has finite image in the abstract commensurator of the subgroup. Using this criterion we exhibit groups that are CAT(0) but not biautomatic. These groups also resolve a number of other questions concerning CAT(0) groups.

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More information

In preparation date: 9 July 2019
Accepted/In Press date: 20 June 2020
Published date: 12 July 2021

Identifiers

Local EPrints ID: 432346
URI: http://eprints.soton.ac.uk/id/eprint/432346
ISSN: 1465-3060
PURE UUID: 453b5de9-c922-453a-894a-1c0bca963fc8
ORCID for Ian Leary: ORCID iD orcid.org/0000-0001-8300-4979
ORCID for Ashot Minasyan: ORCID iD orcid.org/0000-0002-4986-2352

Catalogue record

Date deposited: 11 Jul 2019 16:30
Last modified: 16 Mar 2024 08:01

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