The generator rank of subhomogeneous -algebras

Abstract

Abstract We compute the generator rank of a subhomogeneous $C^*\!$ -algebra in terms of the covering dimension of the pieces of its primitive ideal space corresponding to irreducible representations of a fixed dimension. We deduce that every $\mathcal {Z}$ -stable approximately subhomogeneous algebra has generator rank one, which means that a generic element in such an algebra is a generator. This leads to a strong solution of the generator problem for classifiable, simple, nuclear $C^*\!$ -algebras: a generic element in each such algebra is a generator. Examples of Villadsen show that this is not the case for all separable, simple, nuclear $C^*\!$ -algebras.