1 4 N ov 2 00 8 Scott and Swarup ’ s regular neighbourhood as a tree of cylinders
نویسندگان
چکیده
Let G be a finitely presented group. Scott and Swarup have constructed a canonical splitting of G which encloses all almost invariant sets over virtually polycyclic subgroups of a given length. We give an alternative construction of this regular neighbourhood, by showing that it is the tree of cylinders of a JSJ splitting.
منابع مشابه
1 4 N ov 2 00 8 Trees of cylinders and canonical splittings
Let T be a tree with an action of a finitely generated group G. Given a suitable equivalence relation on the set of edge stabilizers of T (such as commensurability, co-elementarity in a relatively hyperbolic group, or commutation in a commutative transitive group), we define a tree of cylinders Tc. This tree only depends on the deformation space of T ; in particular, it is invariant under autom...
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