{ "id": "2003.10721", "version": "v1", "published": "2020-03-24T08:59:38.000Z", "updated": "2020-03-24T08:59:38.000Z", "title": "A gap of the exponents of repetitions of Sturmian words", "authors": [ "Suzue Ohnaka", "Takao Watanabe" ], "comment": "30 pages", "categories": [ "math.CO" ], "abstract": "By measuring the smallest second occuring time of every factor of an infinite word $x$, Bugeaud and Kim introduced a new quantity ${\\rm rep}(x)$ called the exponent of repetition of $x$. Among other results, Bugeaud and Kim proved that $1 \\leq {\\rm rep}(x) \\leq r_{\\max} = \\sqrt{10} - 3/2$ and $r_{\\max}$ is the isolated maximum value when $x$ varies over the Sturmian words. In this paper, we determine the value $r_1$ such that there is no Sturmian word $x$ satisfying $r_1 < {\\rm rep}(x) < r_{\\max}$ and $r_1$ is an accumulate point of the set of ${\\rm rep}(x)$ when $x$ runs over the Sturmian words.", "revisions": [ { "version": "v1", "updated": "2020-03-24T08:59:38.000Z" } ], "analyses": { "subjects": [ "68R15", "11A55", "11A63" ], "keywords": [ "sturmian word", "repetition", "smallest second occuring time", "accumulate point", "infinite word" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }