Nilpotent extensions of minimal homeomorphisms

Extensions of Nilpotent P.P. Rings

extensions of nilpotent p.p. rings

Full Groups of Minimal Homeomorphisms

We study full groups ofminimal actions of countable groups by homeomorphisms on a Cantor space X, showing that these groups do not admit a compatible Polish group topology and, in the case of Z-actions, are coanalytic non-Borel inside Homeo(X). We then focus on the closure of the full group of a uniquely ergodic homeomorphism, elucidating underwhich conditions this group has a comeager (or, equ...

Crossed Products by Minimal Homeomorphisms

Let X be an infinite compact metric space with finite covering dimension and let h : X → X be a minimal homeomorphism. We show that the associated crossed product C*-algebra A = C∗(Z, X, h) has tracial rank zero whenever the image of K0(A) in Aff(T (A)) is dense. As a consequence, we show that these crossed product C*-algebras are in fact simple AH algebras with real rank zero. When X is connec...

Groups of homeomorphisms of one-manifolds, III: Nilpotent subgroups

This self-contained paper is part of a series [FF1, FF2] seeking to understand groups of homeomorphisms of manifolds in analogy with the theory of Lie groups and their discrete subgroups. Plante-Thurston proved that every nilpotent subgroup of Diff(S) is abelian. One of our main results is a sharp converse: Diff(S) contains every finitely-generated, torsion-free nilpotent group.