{ "id": "1701.06773", "version": "v1", "published": "2017-01-24T09:03:31.000Z", "updated": "2017-01-24T09:03:31.000Z", "title": "Digit frequencies and self-affine sets with non-empty interior", "authors": [ "Simon Baker" ], "categories": [ "math.DS", "math.CA", "math.NT" ], "abstract": "In this paper we study digit frequencies in the setting of expansions in non-integer bases, and self-affine sets with non-empty interior. Within expansions in non-integer bases we show that if $\\beta\\in(1,1.787\\ldots)$ then every $x\\in(0,\\frac{1}{\\beta-1})$ has a simply normal $\\beta$-expansion. We also prove that if $\\beta\\in(1,\\frac{1+\\sqrt{5}}{2})$ then every $x\\in(0,\\frac{1}{\\beta-1})$ has a $\\beta$-expansion for which the digit frequency does not exist, and a $\\beta$-expansion with limiting frequency of zeros $p$, where $p$ is any real number sufficiently close to $1/2$. For a class of planar self-affine sets we show that if the horizontal contraction lies in a certain parameter space and the vertical contractions are sufficiently close to $1,$ then every nontrivial vertical fibre contains an interval. Our approach lends itself to explicit calculation and give rise to new examples of self-affine sets with non-empty interior. One particular strength of our approach is that it allows for different rates of contraction in the vertical direction.", "revisions": [ { "version": "v1", "updated": "2017-01-24T09:03:31.000Z" } ], "analyses": { "subjects": [ "11A63", "28A80", "11K55" ], "keywords": [ "non-empty interior", "digit frequency", "non-integer bases", "nontrivial vertical fibre contains", "study digit frequencies" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }