{ "id": "math/9709217", "version": "v1", "published": "1997-09-18T00:00:00.000Z", "updated": "1997-09-18T00:00:00.000Z", "title": "On asymptotic properties of Banach spaces under renormings", "authors": [ "Edward Odell", "Thomas Schlumprecht" ], "categories": [ "math.FA" ], "abstract": "It is shown that a separable Banach space $X$ can be given an equivalent norm $|\\!|\\!|\\cdot |\\!|\\!|$ with the following properties:\\quad If $(x_n)\\subseteq X$ is relatively weakly compact and $\\lim_{m\\to\\infty} \\lim_{n\\to\\infty}\\break |\\!|\\!| x_m + x_n |\\!|\\!| = 2\\lim_{m\\to\\infty} |\\!|\\!| x_m|\\!|\\!|$ then $(x_n)$ converges in norm. This yields a characterization of reflexivity once proposed by V.D.~Milman. In addition it is shown that some spreading model of a sequence in $(X, |\\!|\\!|\\cdot |\\!|\\!|)$ is 1-equivalent to the unit vector basis of $\\ell_1$ (respectively, $c_0$) implies that $X$ contains an isomorph of $\\ell_1$ (respectively, $c_0$).", "revisions": [ { "version": "v1", "updated": "1997-09-18T00:00:00.000Z" } ], "analyses": { "subjects": [ "46B03", "46B45" ], "keywords": [ "asymptotic properties", "renormings", "unit vector basis", "equivalent norm", "separable banach space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1997math......9217O" } } }