English

Borel lemma: geometric progression and zeta-functions

Classical Analysis and ODEs 2025-05-23 v2

Abstract

In the proof of the classical Borel lemma \cite{eB} by Hayman \cite{wkH}, each continuous increasing function T(r)1T(r)\geq1 satisfies T(r+1T(r))<2T(r)T\bigl(r+\frac{1}{T(r)}\bigr)<2T(r) outside a possible exceptional set of linear measure 22. We note in this work T(r)T(r) satisfies a sharper inequality T(r+1T(r))<(T(r)+1)22T(r)T\bigl(r+\frac{1}{T(r)}\bigr)<\bigl(\sqrt{T(r)}+1\bigr)^2\leq2T(r), if T(r)(2+1)2T(r)\geq\bigl(\sqrt{2}+1\bigr)^2, outside a possible exceptional set of linear measure ζ(2,2+1)0.52<2\zeta\bigl(2,\sqrt{2}+1\bigr)\leq0.52<2 for the Hurwitz zeta-function ζ(s,a)\zeta(s,a). This result is worth noting, provided the set of rr in which 1T(r)<(2+1)21\leq T(r)<\bigl(\sqrt{2}+1\bigr)^2 has linear measure less than 1.481.48. Focusing exclusively on meromorphic functions of infinite order, we utilize Hinkkanen's Second Main Theorem \cite{aH}, draw comparisons with Borel \cite{eB}, Nevanlinna \cite{rN}, and Hayman \cite{wkH}, and finally generalize Fern\'{a}ndez \'{A}rias \cite{aFA1}.

Keywords

Cite

@article{arxiv.2401.14481,
  title  = {Borel lemma: geometric progression and zeta-functions},
  author = {Qi Han and Jingbo Liu and Nadeem Malik},
  journal= {arXiv preprint arXiv:2401.14481},
  year   = {2025}
}
R2 v1 2026-06-28T14:27:33.090Z