Uniform random covering problems (2103.01595v1)

Abstract: Motivated by the random covering problem and the study of Dirichlet uniform approximable numbers, we investigate the uniform random covering problem. Precisely, consider an i.i.d. sequence $\omega=(\omega_n){n\geq 1}$ uniformly distributed on the unit circle $\mathbb{T}$ and a sequence $(r_n){n\geq 1}$ of positive real numbers with limit $0$. We investigate the size of the random set [ \mathcal U (\omega):={y\in \mathbb{T}: \ \forall N\gg 1, \ \exists n \leq N, \ \text{s.t.} \ | \omega_n -y | < r_N }. ] Some sufficient conditions for $\mathcal U(\omega)$ to be almost surely the whole space, of full Lebesgue measure, or countable, are given. In the case that $\mathcal U(\omega)$ is a Lebesgue null measure set, we provide some estimations for the upper and lower bounds of Hausdorff dimension.