Abstract
It is shown that the class of amenable (resp. strongly amenable)C*-algebras is closed under the process of taking crossed products with discrete amenable groups. Under certain circumstances, amenability is also preserved under taking a “crossed product” with an amenable semigroup of linear endomorphisms. These facts are used to show that certain simpleC*-algebras\(\mathcal{O}_n \) studied by J. Cuntz are amenable but not strongly amenable (thus answering a question of B. E. Johnson), yet are stably isomorphic to strongly amenable algebras.
Similar content being viewed by others
References
Brown, L.G., Green, P., Rieffel, M.A.: Stable isomorphism and strong Morita equivalence ofC*-algebras. Pacific J. Math.71, 349–364 (1977)
Bunce, J.: Characterizations of amenable and strongly amenableC*-algebras. Pacific J. Math.43, 563–572 (1972)
Connes, A.: On the cohomology of operator algebras. Preprint
Cuntz, J.: SimpleC*-algebras generated by isometries. Commun. math. Phys.57, 173–185 (1977)
Dixmier, J.: Traces sur lesC*-algèbres II. Bull. Sci. Math.88, 39–57 (1964)
Glimm, J.G.: On a certain class of operator algebras. Trans. Am. Math. Soc.95, 318–340 (1960)
Johnson, B.E.: Cohomology in Banach algebras. Mem. Am. Math. Soc.127 (1972)
Ringrose, J.: Automatic continuity of derivations of operator algebras. J. London Math. Soc.5, 432–438 (1972)
Author information
Authors and Affiliations
Additional information
Communicated by H. Araki
Partially supported by NSF
Rights and permissions
About this article
Cite this article
Rosenberg, J. Amenability of crossed products ofC*-algebras. Commun.Math. Phys. 57, 187–191 (1977). https://doi.org/10.1007/BF01625777
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01625777