{ "id": "1903.03417", "version": "v1", "published": "2019-03-08T13:17:27.000Z", "updated": "2019-03-08T13:17:27.000Z", "title": "Power bounded $m$-left invertible operators", "authors": [ "B. P. Duggal", "C. S. Kubrusly" ], "comment": "10", "categories": [ "math.FA" ], "abstract": "A Hilbert space operator $S\\in\\B$ is left $m$-invertible by $T\\in\\B$ if $$\\sum_{j=0}^m{(-1)^{m-j}\\left(\\begin{array}{clcr}m\\\\j\\end{array}\\right)T^jS^j}=0,$$ $S$ is $m$-isometric if $$\\sum_{j=0}^m{(-1)^{m-j}\\left(\\begin{array}{clcr}m\\\\j\\end{array}\\right){S^*}^jS^j}=0$$ and $S$ is $(m,C)$-isometric for some conjugation $C$ of $\\H$ if $$\\sum_{j=0}^m{(-1)^{m-j}\\left(\\begin{array}{clcr}m\\\\j\\end{array}\\right){S^*}^jCS^jC}=0.$$ If a power bounded operator $S$ is left invertible by a power bounded operator $T$, then $S$ (also, $T^*$) is similar to an isometry. Translated to $m$-isometric and $(m,C)$-isometric operators $S$ this implies that $S$ is $1$-isometric, equivalently isometric, and (respectively) $(1,C)$-isometric.", "revisions": [ { "version": "v1", "updated": "2019-03-08T13:17:27.000Z" } ], "analyses": { "subjects": [ "47A05", "47A55", "47A80", "47A10" ], "keywords": [ "left invertible operators", "power bounded operator", "hilbert space operator", "isometric operators", "conjugation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }