English

Full dimensional sets of reals whose sums of partial quotients increase in certain speed

Number Theory 2019-11-15 v3

Abstract

For a real x(0,1)Qx\in(0,1)\setminus\mathbb{Q}, let x=[a1(x),a2(x),]x=[a_1(x),a_2(x),\cdots] be its continued fraction expansion. Let sn(x)=j=1naj(x)s_n(x)=\sum_{j=1}^n a_j(x). The Hausdorff dimensions of the level sets Eφ(n),α:={x(0,1):limnsn(x)φ(n)=α}E_{\varphi(n),\alpha}:=\{x\in(0,1): \lim_{n\rightarrow\infty}\frac{s_n(x)}{\varphi(n)}=\alpha\} for α0\alpha\geq 0 and a non-decreasing sequence {φ(n)}n=1\{\varphi(n)\}_{n=1}^\infty have been studied by E. Cesaratto, B. Vall\'ee, J. Wu, J. Xu, G. Iommi, T. Jordan, L. Liao, M. Rams \emph{et al}. In this work we carry out a kind of inverse project of their work, that is, we consider the conditions on φ(n)\varphi(n) under which one can expect a 11-dimensional set Eφ(n),αE_{\varphi(n),\alpha}. We give certain upper and lower bounds on the increasing speed of φ(n)\varphi(n) when Eφ(n),αE_{\varphi(n),\alpha} is of Hausdorff dimension 1 and a new class of sequences {φ(n)}n=1\{\varphi(n)\}_{n=1}^\infty such that Eφ(n),αE_{\varphi(n),\alpha} is of full dimension. There is also a discussion of the problem in the irregular case.

Keywords

Cite

@article{arxiv.1610.02754,
  title  = {Full dimensional sets of reals whose sums of partial quotients increase in certain speed},
  author = {Liangang Ma},
  journal= {arXiv preprint arXiv:1610.02754},
  year   = {2019}
}