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arXiv · 2010.07364

On periodicity of $p$-adic Browkin continued fractions

Laura Capuano·Nadir Murru·Lea Terracini
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Abstract

The classical theory of continued fractions has been widely studied for centuries for its important properties of good approximation, and more recently it has been generalized to $p$-adic numbers where it presents many differences with respect to the real case. In this paper we investigate periodicity for the $p$-adic continued fractions introduced by Browkin. We give some necessary and sufficient conditions for periodicity in general, although a full characterization of $p$-adic numbers having purely periodic Browkin continued fraction expansion is still missing. In the second part of the paper, we describe a general procedure to construct square roots of integers having periodic Browkin $p$-adic continued fraction expansion of prescribed even period length. As a consequence, we prove that, for every $n \ge 1$, there exist infinitely many $\sqrt{m}\in \QQ_p$ with periodic Browkin expansion of period $2^n$, extending a previous result of Bedocchi obtained for $n=1$.

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Laura Capuano, Nadir Murru, Lea Terracini. 2020-10-14. On periodicity of $p$-adic Browkin continued fractions. https://arxiv.org/abs/2010.07364

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