English

Rotations by roots of unity and Diophantine approximation

Number Theory 2020-05-04 v1

Abstract

For a fixed integer nn, we study the question whether at least one of the numbers Xωk\Re X\omega^k, 1kn1\leq k\leq n, is ε\varepsilon-close to an integer, for any possible value of XCX\in\mathbb{C}, where ω\omega is a primitive nnth root of unity. It turns out that there is always a XX for which the above numbers are concentrated around 1/2mod11/2\bmod1. The distance from 1/21/2 depends only on the local properties of nn, rather than its magnitude. This is directly related the so-called "pyjama" problem which was solved recently.

Keywords

Cite

@article{arxiv.1510.03645,
  title  = {Rotations by roots of unity and Diophantine approximation},
  author = {Romanos-Diogenes Malikiosis},
  journal= {arXiv preprint arXiv:1510.03645},
  year   = {2020}
}

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7 pages