{ "id": "1407.1275", "version": "v1", "published": "2014-07-04T17:00:25.000Z", "updated": "2014-07-04T17:00:25.000Z", "title": "Characterisation of Cesàro and $L$-Asymptotic Limits of Matrices", "authors": [ "György Pál Gehér" ], "comment": "15 pages, Linear and Multilinear Algebra(2014)", "doi": "10.1080/03081087.2014.899359", "categories": [ "math.FA" ], "abstract": "The main goal of this paper is to characterise all the possible Ces\\`aro and $L$-asymptotic limits of powerbounded, complex matrices. The investigation of the $L$-asymptotic limit of a powerbounded operator goes back to Sz.-Nagy and it shows how the orbit of a vector behaves with respect to the powers. It turns out that the two types of asymptotic limits coincide for every powerbounded matrix and a special case is connected to the description of the products $SS^*$ where $S$ runs through those invertible matrices which have unit columnvectors. We also show that for any powerbounded operator acting on an arbitrary complex Hilbert space the norm of the $L$-asymptotic limit is greater than or equal to 1, unless it is zero; moreover, the same is true for the Ces\\`aro asymptotic limit of a not necessarily powerbounded operator, if it exists.", "revisions": [ { "version": "v1", "updated": "2014-07-04T17:00:25.000Z" } ], "analyses": { "subjects": [ "47A45", "47B65" ], "keywords": [ "powerbounded operator", "characterisation", "arbitrary complex hilbert space", "asymptotic limits coincide", "special case" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1407.1275P" } } }