Exactness of reduced amalgamated free product C* -algebras

Exactness of Reduced Amalgamated Free Product C {algebras

Some completely positive maps on reduced amalgamated free products of C∗–algebras are constructed, showing that every reduced amalgamated free product of exact C∗–algebras is exact. Consequently, every amalgamated free product of exact discrete groups is exact.

On Embeddings of Full Amalgamated Free Product C∗–algebras

An embedding question for full (i.e. universal) amalgamated free products of C∗–algebras is raised, and solved in part. This is used to give a necessary and sufficient condition for the full amalgamated free product of finite dimensional C∗–algebras to be residually finite dimensional.

Topological Entropy of Some Automorphisms of Reduced Amalgamated Free Product C–algebras

Certain classes of automorphisms of reduced amalgamated free products of C∗– algebras are shown to have Brown–Voiculescu topological entropy zero. Also, for automorphisms of exact C∗–algebras, the Connes–Narnhofer–Thirring entropy is shown to be bounded above by the Brown–Voiculescu entropy. These facts are applied to generalize Størmer’s result about the entropy of automorphisms of the II1–fac...

Institute for Mathematical Physics Topological Entropy of Some Automorphisms of Reduced Amalgamated Free Product C {algebras

On the Structure of Some Reduced Amalgamated Free Product C-algebras

We study some reduced free products of C∗-algebras with amalgamations. We give sufficient conditions for the positive cone of the K0 group to be the largest possible. We also give sufficient conditions for simplicity and uniqueness of trace. We use the later result to give a necessary and sufficient condition for simplicity and uniqueness of trace of the reduced C∗-algebras of the Baumslag-Soli...