Inhomogeneous Diophantine approximation in the coprime setting

Abstract

Given $n\in N$ and $x,\gamma\in R$, let \begin{equation*} ||\gamma-nx||^\prime=\min\{|\gamma-nx+m|:m\in Z, \gcd (n,m)=1\}, \end{equation*} %where $(n,m)$ is the largest common divisor of $n$ and $m$. Two conjectures in the coprime inhomogeneous Diophantine approximation state that for any irrational number $\alpha$ and almost every $\gamma\in R$, \begin{equation*} \liminf_{n\to \infty}n||\gamma -n\alpha||^{\prime}=0 \end{equation*} and that there exists $C>0$, such that for all $\alpha\in R\backslash Q$ and $\gamma\in [0,1)$ , \begin{equation*} \liminf_{n\to \infty}n||\gamma -n\alpha||^{\prime} < C. \end{equation*} We prove the first conjecture and disprove the second one.