z-logo
open-access-imgOpen Access
Deformation spaces of $G$-trees and automorphisms of Baumslag–Solitar groups
Author(s) -
Matt Clay
Publication year - 2009
Publication title -
groups geometry and dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 25
eISSN - 1661-7215
pISSN - 1661-7207
DOI - 10.4171/ggd/51
Subject(s) - automorphism , mathematics , computation , finitely generated abelian group , algebraic number , invariant (physics) , pure mathematics , automorphism group , combinatorics , mathematical analysis , algorithm , mathematical physics
We construct an invariant deformation retract of a deformation space ofG-trees. We show that this complex is finite dimensional in certain cases andprovide an example that is not finite dimensional. Using this complex wecompute the automorphism group of the classical non-solvable Baumslag-Solitargroups BS(p,q). The most interesting case is when p properly divides q. Collinsand Levin computed a presentation for Aut(BS(p,q)) in this case using algebraicmethods. Our computation uses Bass-Serre theory to derive these presentations.Additionally, we provide a geometric argument showing Out(BS(p,q)) is notfinitely generated when p properly divides q.

The content you want is available to Zendy users.

Already have an account? Click here to sign in.
Having issues? You can contact us here
Accelerating Research

Address

John Eccles House
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom