{ "id": "2203.08179", "version": "v1", "published": "2022-03-15T18:13:03.000Z", "updated": "2022-03-15T18:13:03.000Z", "title": "Free outer functions in complete Pick spaces", "authors": [ "Alexandru Aleman", "Michael Hartz", "John E. McCarthy", "Stefan Richter" ], "comment": "63 pages", "categories": [ "math.FA", "math.CV" ], "abstract": "Jury and Martin establish an analogue of the classical inner-outer factorization of Hardy space functions. They show that every function $f$ in a Hilbert function space with a normalized complete Pick reproducing kernel has a factorization of the type $f=\\varphi g$, where $g$ is cyclic, $\\varphi$ is a contractive multiplier, and $\\|f\\|=\\|g\\|$. In this paper we show that if the cyclic factor is assumed to be what we call free outer, then the factors are essentially unique, and we give a characterization of the factors that is intrinsic to the space. That lets us compute examples. We also provide several applications of this factorization.", "revisions": [ { "version": "v1", "updated": "2022-03-15T18:13:03.000Z" } ], "analyses": { "subjects": [ "46E22", "47A16", "47B32" ], "keywords": [ "free outer functions", "complete pick spaces", "normalized complete pick reproducing kernel", "hilbert function space", "hardy space functions" ], "note": { "typesetting": "TeX", "pages": 63, "language": "en", "license": "arXiv", "status": "editable" } } }