{ "id": "0801.2477", "version": "v1", "published": "2008-01-16T16:40:31.000Z", "updated": "2008-01-16T16:40:31.000Z", "title": "Stability and instability of weighted composition operators", "authors": [ "Jesus Araujo", "Juan J. Font" ], "comment": "37 pages, 7 figures. A beamer presentation at http://www.araujo.tk", "categories": [ "math.FA" ], "abstract": "Let $\\epsilon >0$. A continuous linear operator $T:C(X) \\ra C(Y)$ is said to be {\\em $\\epsilon$-disjointness preserving} if $\\vc (Tf)(Tg)\\vd_{\\infty} \\le \\epsilon$, whenever $f,g\\in C(X)$ satisfy $\\vc f\\vd_{\\infty} =\\vc g\\vd_{\\infty} =1$ and $fg\\equiv 0$. In this paper we address basically two main questions: 1.- How close there must be a weighted composition operator to a given $\\epsilon$-disjointness preserving operator? 2.- How far can the set of weighted composition operators be from a given $\\epsilon$-disjointness preserving operator? We address these two questions distinguishing among three cases: $X$ infinite, $X$ finite, and $Y$ a singleton ($\\epsilon$-disjointness preserving functionals). We provide sharp stability and instability bounds for the three cases.", "revisions": [ { "version": "v1", "updated": "2008-01-16T16:40:31.000Z" } ], "analyses": { "subjects": [ "47B38", "46J10", "47B33" ], "keywords": [ "weighted composition operator", "disjointness preserving operator", "disjointness preserving functionals", "sharp stability", "main questions" ], "note": { "typesetting": "TeX", "pages": 37, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0801.2477A" } } }