{ "id": "1305.1827", "version": "v1", "published": "2013-05-08T14:25:33.000Z", "updated": "2013-05-08T14:25:33.000Z", "title": "Notes on the Krupa-Zawisza Ultrapower of Self-Adjoint Operators", "authors": [ "Hiroshi Ando", "Izumi Ojima", "Hayato Saigo" ], "comment": "13pages", "categories": [ "math.FA" ], "abstract": "It is known that there is a difficulty in constructing the ultrapower of unbounded operators. Krupa and Zawisza gave a rigorous definition of the ultrapower A^{omega} of a selfadjoint operator A. In this note, we give alternative description of A^{omega} and the Hilbert space H(A) on which A^{omega} is densely defined, which provides a criterion to determine to which representing sequence (\\xi_n)n of a given vector \\xi in dom(A^{omega}) has the property that A^{omega}\\xi = (A\\xi_n)_{omega} holds.", "revisions": [ { "version": "v1", "updated": "2013-05-08T14:25:33.000Z" } ], "analyses": { "subjects": [ "47A10", "03C20" ], "keywords": [ "self-adjoint operators", "krupa-zawisza ultrapower", "hilbert space", "selfadjoint operator", "zawisza gave" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1305.1827A" } } }