{ "id": "0906.1162", "version": "v1", "published": "2009-06-05T16:28:13.000Z", "updated": "2009-06-05T16:28:13.000Z", "title": "Systems formed by translates of one element in $L_p(\\mathbb R)$", "authors": [ "E. Odell", "B. Sari", "Th. Schlumprecht", "B. Zheng" ], "categories": [ "math.FA" ], "abstract": "Let $1\\le p <\\infty$, $f\\in L_p(\\real)$ and $\\Lambda\\subseteq \\real$. We consider the closed subspace of $L_p(\\real)$, $X_p (f,\\Lambda)$, generated by the set of translations $f_{(\\lambda)}$ of $f$ by $\\lambda \\in\\Lambda$. If $p=1$ and $\\{f_{(\\lambda)} :\\lambda\\in\\Lambda\\}$ is a bounded minimal system in $L_1(\\real)$, we prove that $X_1 (f,\\Lambda)$ embeds almost isometrically into $\\ell_1$. If $\\{f_{(\\lambda)} :\\lambda\\in\\Lambda\\}$ is an unconditional basic sequence in $L_p(\\real)$, then $\\{f_{(\\lambda)} : \\lambda\\in\\Lambda\\}$ is equivalent to the unit vector basis of $\\ell_p$ for $1\\le p\\le 2$ and $X_p (f,\\Lambda)$ embeds into $\\ell_p$ if $2
4$, there exists $f\\in L_p(\\real)$ and $\\Lambda \\subseteq \\zed$ so that $\\{f_{(\\lambda)} :\\lambda\\in\\Lambda\\}$ is unconditional basic and $L_p(\\real)$ embeds isomorphically into $X_p (f,\\Lambda)$.", "revisions": [ { "version": "v1", "updated": "2009-06-05T16:28:13.000Z" } ], "analyses": { "keywords": [ "translates", "unconditional basic sequence", "unit vector basis", "bounded minimal system" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0906.1162O" } } }