{ "id": "1407.7160", "version": "v1", "published": "2014-07-26T21:14:02.000Z", "updated": "2014-07-26T21:14:02.000Z", "title": "On extensions of $J$-skew-symmetric and $J$-isometric operators", "authors": [ "Sergey M. Zagorodnyuk" ], "comment": "5 pages", "categories": [ "math.FA" ], "abstract": "In this paper it is proved that each densely defined $J$-skew-symmetric operator (or each $J$-isometric operator with $\\overline{D(A)}=\\overline{R(A)}=H$) in a Hilbert space $H$ has a $J$-skew-self-adjoint (respectively $J$-unitary) extension in a Hilbert space $\\widetilde H\\supseteq H$. We follow the ideas of Galindo in~[A.~Galindo, On the existence of $J$-self-adjoint extensions of $J$-symmetric operators with adjoint, Communications on pure and applied mathematics, Vol. XV, 423-425 (1962)] with necessary modifications.", "revisions": [ { "version": "v1", "updated": "2014-07-26T21:14:02.000Z" } ], "analyses": { "subjects": [ "47A20" ], "keywords": [ "isometric operator", "hilbert space", "skew-symmetric operator", "necessary modifications", "self-adjoint extensions" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1407.7160Z" } } }