English

Distribution of integral values for the ratio of two linear recurrences

Number Theory 2017-08-29 v1

Abstract

Let FF and GG be linear recurrences over a number field K\mathbb{K}, and let R\mathfrak{R} be a finitely generated subring of K\mathbb{K}. Furthermore, let N\mathcal{N} be the set of positive integers nn such that G(n)0G(n) \neq 0 and F(n)/G(n)RF(n) / G(n) \in \mathfrak{R}. Under mild hypothesis, Corvaja and Zannier proved that N\mathcal{N} has zero asymptotic density. We prove that #(N[1,x])x(loglogx/logx)h\#(\mathcal{N} \cap [1, x]) \ll x \cdot (\log\log x / \log x)^h for all x3x \geq 3, where hh is a positive integer that can be computed in terms of FF and GG. Assuming the Hardy-Littlewood kk-tuple conjecture, our result is optimal except for the term loglogx\log \log x.

Keywords

Cite

@article{arxiv.1703.10047,
  title  = {Distribution of integral values for the ratio of two linear recurrences},
  author = {Carlo Sanna},
  journal= {arXiv preprint arXiv:1703.10047},
  year   = {2017}
}