On the rate of accumulation of $\alpha\zeta^{n}$ mod 1 to 0

Abstract

In this paper we study the distribution of the sequence $(\alpha \zeta^{n})_{n\geq 1}$ mod $1$, where $\alpha,\zeta$ are fixed positive real numbers, with special focus on the accumulation point $0$. For this purpose we introduce approximation constants $\underline{\sigma}(\alpha,\zeta),\overline{\sigma}(\alpha, \zeta)$ and study their properties in dependence of $\alpha,\zeta$, distinguishing in particular the cases of Pisot numbers, algebraic non Pisot numbers and transcendental values of $\alpha$ as well as $\zeta$.