paper

C*-algebras associated with endomorphisms and polymorphisms of compact abelian groups

arXiv:1202.5960 · doi:10.1007/s00220-012-1647-0

Abstract

A surjective endomorphism or, more generally, a polymorphism in the sense of \cite{SV}, of a compact abelian group induces a transformation of . We study the C*-algebra generated by this operator together with the algebra of continuous functions which acts as multiplication operators on . Under a natural condition on the endo- or polymorphism, this algebra is simple and can be described by generators and relations. In the case of an endomorphism it is always purely infinite, while for a polymorphism in the class we consider, it is either purely infinite or has a unique trace. We prove a formula allowing to determine the -theory of these algebras and use it to compute the -groups in a number of interesting examples.

25 pages

References in corpus (4)

Cited by in corpus (12)