Cuntz semigroups of ultraproduct C*-algebras

We prove that the category of abstract Cuntz semigroups is bicomplete. As a consequence, the category admits products and ultraproducts. We further show that the scaled Cuntz semigroup of the (ultra)product of a family of C∗-algebras agrees with the (ultra)product of the scaled Cuntz semigroups of t...

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Detalles Bibliográficos
Autores: Antoine Riolobos, Ramon|||0000-0002-0062-5938, Perera Domènech, Francesc|||0000-0002-4669-4736, Thiel, Hannes
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:306045
Acceso en línea:https://ddd.uab.cat/record/306045
https://dx.doi.org/urn:doi:10.1112/jlms.12343
Access Level:acceso abierto
Palabra clave:Cuntz semigroup
Continuous poset
C∗-algebra
Ultraproducts
Descripción
Sumario:We prove that the category of abstract Cuntz semigroups is bicomplete. As a consequence, the category admits products and ultraproducts. We further show that the scaled Cuntz semigroup of the (ultra)product of a family of C∗-algebras agrees with the (ultra)product of the scaled Cuntz semigroups of the involved C∗-algebras. As applications of our results, we compute the non-stable K-Theory of general (ultra)products of C∗-algebras and we characterize when ultraproducts are simple. We also give criteria that determine order properties of these objects, such as almost unperforation.