It has recently been proved that the class of unital exact C*-algebras is closed under taking reduced amalgamated free products. Here the proof is presented of a special case: that the class of exact discrete groups is closed under taking free products (with amalgamation over the identity element). The proof of this special case is considerably simpler than in full generality.

We give a construction of a nuclear C*-algebra associated with an amalgamated free product of groups, generalizing Spielberg's construction of a certain Cuntz-Krieger algebra associated with a… Expand

Uniform embeddability (in a Hilbert space), introduced by Gromov, is a geometric property of metric spaces. As applied to countable discrete groups, it has important consequences for the Novikov… Expand

Since Grothendieck showed in [18] that the theory of tensor products of locally convex spaces gives important informations on functional analytic properties of locally convex vector spaces, it was… Expand

We present an example which illustrates several peculiar phenomena that may occur in the theory of C*-algebras. In particular, we show that a C*-subalgebra of a nuclear (amenable) C*-algebra need not… Expand