On upper and lower fast Knintchine spectra of continued fractions

Lulu Fang, Lei Shang, Min Wu

Let $\psi :\mathbb{N}\to {\mathbb{R}}^{+}$ be a function satisfying $\varphi (n)/n\to \infty$ as $n\to \infty$. We investigate from a multifractal analysis point of view the growth rate of the s…