{ "id": "1101.4320", "version": "v2", "published": "2011-01-22T20:32:59.000Z", "updated": "2012-02-27T20:51:36.000Z", "title": "Multi-norms and the injectivity of $L^p(G)$", "authors": [ "H. Garth Dales", "Matthew Daws", "Hung Le Pham", "Paul Ramsden" ], "comment": "31 pages; minor typographical and mathematical corrections", "categories": [ "math.FA" ], "abstract": "Let $G$ be a locally compact group, and take $p\\in(1,\\infty)$. We prove that the Banach left $L^1(G)$-module $L^p(G)$ is injective (if and) only if the group $G$ is amenable. Our proof uses the notion of multi-norms. We also develop the theory of multi-normed spaces.", "revisions": [ { "version": "v2", "updated": "2012-02-27T20:51:36.000Z" } ], "analyses": { "subjects": [ "46H25", "43A20" ], "keywords": [ "multi-norms", "injectivity", "banach left", "locally compact group" ], "note": { "typesetting": "TeX", "pages": 31, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1101.4320D" } } }