{ "id": "1204.2046", "version": "v1", "published": "2012-04-10T05:17:39.000Z", "updated": "2012-04-10T05:17:39.000Z", "title": "Orbits of linear operators and Banach space geometry", "authors": [ "Jean-Matthieu Augé" ], "comment": "16 pages", "categories": [ "math.FA" ], "abstract": "Let $T$ be a bounded linear operator on a (real or complex) Banach space $X$. If $(a_n)$ is a sequence of non-negative numbers tending to 0. Then, the set of $x \\in X$ such that $\\|T^nx\\| \\geqslant a_n \\|T^n\\|$ for infinitely many $n$'s has a complement which is both $\\sigma$-porous and Haar-null. We also compute (for some classical Banach space) optimal exponents $q>0$, such that for every non nilpotent operator $T$, there exists $x \\in X$ such that $(\\|T^nx\\|/\\|T^n\\|) \\notin \\ell^{q}(\\mathbb{N})$, using techniques which involve the modulus of asymptotic uniform smoothness of $X$.", "revisions": [ { "version": "v1", "updated": "2012-04-10T05:17:39.000Z" } ], "analyses": { "subjects": [ "47A05", "47A16", "28A05" ], "keywords": [ "banach space geometry", "non nilpotent operator", "asymptotic uniform smoothness", "bounded linear operator", "classical banach space" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1204.2046A" } } }