{ "id": "1706.00701", "version": "v1", "published": "2017-06-02T14:40:38.000Z", "updated": "2017-06-02T14:40:38.000Z", "title": "Homomorphisms with small bound between Fourier algebras", "authors": [ "Yulia Kuznetsova", "Jean Roydor" ], "journal": "Israel Journal of Mathematics Isreal J. Math. 217 (2017), Iss. 1, pp. 283-301", "categories": [ "math.FA" ], "abstract": "Inspired by Kalton and Wood's work on group algebras, we describe almost completely contractive algebra homomorphisms from Fourier algebras into Fourier-Stieltjes algebras (endowed with their canonical operator space structure). We also prove that two locally compact groups are isomorphic if and only if there exists an algebra isomorphism $T$ between the associated Fourier algebras (resp. Fourier-Stieltjes algebras) with completely bounded norm $\\| T \\|_{cb} < \\sqrt {3/2}$ (resp. $ \\| T \\|_{cb} < \\sqrt {5}/2$). We show similar results involving the norm distortion $\\| T \\| \\| T ^{-1} \\|$ with universal but non-explicit bound. Our results subsume Walter's well-known structural theorems and also Lau's theorem on second conjugate of Fourier algebras.", "revisions": [ { "version": "v1", "updated": "2017-06-02T14:40:38.000Z" } ], "analyses": { "subjects": [ "46L05", "46L10", "46L07", "46L25" ], "keywords": [ "fourier algebras", "small bound", "subsume walters well-known structural theorems", "homomorphisms", "results subsume walters well-known structural" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }