{ "id": "2301.02391", "version": "v1", "published": "2023-01-06T05:55:26.000Z", "updated": "2023-01-06T05:55:26.000Z", "title": "On effective irrationality exponents of cubic irrationals", "authors": [ "Dzmitry Badziahin" ], "comment": "17 pages", "categories": [ "math.NT" ], "abstract": "We provide an upper bound on the efficient irrationality exponents of cubic algebraics $x$ with the minimal polynomial $x^3 - tx^2 - a$. In particular, we show that it becomes non-trivial, i.e. better than the classical bound of Liouville in the case $|t| > 19.71 a^{4/3}$. Moreover, under the condition $|t| > 86.58 a^{4/3}$, we provide an explicit lower bound on the expression $||qx||$ for all large $q\\in\\mathbb{Z}$. These results are based on the recently discovered continued fractions of cubic irrationals and improve the currently best-known bounds of Wakabayashi.", "revisions": [ { "version": "v1", "updated": "2023-01-06T05:55:26.000Z" } ], "analyses": { "subjects": [ "11J68", "11J70", "11J82" ], "keywords": [ "effective irrationality exponents", "cubic irrationals", "efficient irrationality exponents", "explicit lower bound", "cubic algebraics" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }