{ "id": "0905.0739", "version": "v2", "published": "2009-05-06T13:05:31.000Z", "updated": "2012-05-02T21:03:21.000Z", "title": "Irregular sets, the $β$-transformation and the almost specification property", "authors": [ "Daniel J. Thompson" ], "comment": "To appear in Transactions of the American Mathematical Society. Final version was submitted to TAMS on November 24th 2010, and it appears I did not update the arXiv version at the time! Changes from version 1 are mostly minor - typos fixed, references improved. The most significant change is to section 5.1, where the results have been improved", "categories": [ "math.DS" ], "abstract": "Let $(X,d)$ be a compact metric space, $f:X \\mapsto X$ be a continuous map satisfying a property we call almost specification (which is slightly weaker than the $g$-almost product property of Pfister and Sullivan), and $\\phi$ be a continuous function on $X$. We show that the set of points for which the Birkhoff average of $\\phi$ does not exist (which we call the irregular set) is either empty or has full topological entropy. Every $\\beta$-shift satisfies almost specification and we show that the irregular set for any $\\beta$-shift or $\\beta$-transformation is either empty or has full topological entropy and Hausdorff dimension.", "revisions": [ { "version": "v2", "updated": "2012-05-02T21:03:21.000Z" } ], "analyses": { "subjects": [ "37C45" ], "keywords": [ "irregular set", "specification property", "transformation", "full topological entropy", "compact metric space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0905.0739T" } } }