{ "id": "1812.00164", "version": "v1", "published": "2018-12-01T07:16:43.000Z", "updated": "2018-12-01T07:16:43.000Z", "title": "Parallelism in Hilbert $K(\\mathcal{H})$-modules", "authors": [ "M. Mohammadi Gohari", "M. Amyari" ], "categories": [ "math.FA" ], "abstract": "Let $(\\mathcal{H}, [\\cdot, \\cdot ])$ be a Hilbert space and $K(\\mathcal{H})$ be the $C^*$-algebra of compact operators on $\\mathcal{H}$. In this paper, we present some characterizations of the norm-parallelism for elements of a Hilbert $K(\\mathcal{H})$-module $\\mathcal{E}$ by employing the minimal projections on $\\mathcal{H}$. Let $T,S\\in \\mathcal{L(\\mathcal{E})}$. We show that $T \\| S$ if and only if there exists a sequence of basic vectors $\\{x_n\\}^{\\xi_n}$ in $\\mathcal{E}$ such that $\\lim_n [\\langle Tx_n, Sx_n \\rangle \\xi_n, \\xi_n ] = \\lambda\\| T\\| \\| S\\|$ for some $\\lambda \\in \\mathbb{T}$. In addition, we give some equivalence assertions about the norm-parallelism of \"compact\" operators on a Hilbert $C^*$-module.", "revisions": [ { "version": "v1", "updated": "2018-12-01T07:16:43.000Z" } ], "analyses": { "subjects": [ "46L08", "47A30", "47B10", "47B47" ], "keywords": [ "compact operators", "norm-parallelism", "hilbert space", "minimal projections", "basic vectors" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }