{ "id": "1704.04939", "version": "v1", "published": "2017-04-17T11:54:13.000Z", "updated": "2017-04-17T11:54:13.000Z", "title": "Cartan subalgebras and the UCT problem, II", "authors": [ "Selcuk Barlak", "Xin Li" ], "comment": "26 pages", "categories": [ "math.OA", "math.KT" ], "abstract": "We show that outer approximately represenbtable actions of a finite cyclic group on UCT Kirchberg algebras satisfy a certain quasi-freeness type property if the corresponding crossed products satisfy the UCT and absorb a suitable UHF algebra tensorially. More concretely, we prove that for such an action there exists an inverse semigroup of homogeneous partial isometries that generates the ambient C*-algebra and whose idempotent semilattice generates a Cartan subalgebra. We prove a similar result for actions of finite cyclic groups with the Rokhlin property on UCT Kirchberg algebras absorbing a suitable UHF algebra. These results rely on a new construction of Cartan subalgebras in certain inductive limits of Cartan pairs. We also provide a characterisation of the UCT problem in terms of finite order automorphisms, Cartan subalgebras and inverse semigroups of partial isometries of the Cuntz algebra $\\mathcal{O}_2$. This generalizes earlier work of the authors.", "revisions": [ { "version": "v1", "updated": "2017-04-17T11:54:13.000Z" } ], "analyses": { "subjects": [ "46L05", "46L40", "46L80", "19K35" ], "keywords": [ "cartan subalgebra", "uct problem", "finite cyclic group", "suitable uhf algebra", "uct kirchberg algebras satisfy" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable" } } }