{ "id": "1009.3921", "version": "v3", "published": "2010-09-20T19:38:40.000Z", "updated": "2013-12-18T21:59:55.000Z", "title": "Operator monotone functions and Löwner functions of several variables", "authors": [ "Jim Agler", "John E. McCarthy", "Nicholas J. Young" ], "journal": "Annals of Mathematics (2) 176 [2012] no. 3, 1783-1826", "categories": [ "math.FA", "math.CV" ], "abstract": "We prove generalizations of L\\\"owner's results on matrix monotone functions to several variables. We give a characterization of when a function of $d$ variables is locally monotone on $d$-tuples of commuting self-adjoint $n$-by-$n$ matrices. We prove a generalization to several variables of Nevanlinna's theorem describing analytic functions that map the upper half-plane to itself and satisfy a growth condition. We use this to characterize all rational functions of two variables that are operator monotone.", "revisions": [ { "version": "v3", "updated": "2013-12-18T21:59:55.000Z" } ], "analyses": { "subjects": [ "47A63", "32A35" ], "keywords": [ "operator monotone functions", "löwner functions", "nevanlinnas theorem describing analytic functions", "matrix monotone functions", "growth condition" ], "tags": [ "journal article" ], "publication": { "publisher": "Princeton University and the Institute for Advanced Study", "journal": "Ann. Math." }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1009.3921A" } } }