Uniformly perfect sets and distortion of holomorphic functions

Abstract

We investigate the uniform perfectness on a boundary point of a hyperbolic open set and distortion of a holomorphic function from the unit disk $\Delta$ into a hyperbolic domain with a uniformly perfect boundary point, especially of a universal covering map of such a domain from $\Delta$, and we obtain similar results to celebrated Koebe's Theorems on univalent functions.