Normal families and linear differential equation

TL;DR

This paper proves that a family of analytic functions with a spherical derivative bounded away from zero is normal, establishing a key condition for normality in complex analysis.

Contribution

It introduces a new criterion linking the spherical derivative's lower bound to the normality of function families.

Findings

Family of functions with spherical derivative > c is normal

Provides a sufficient condition for normality in complex analysis

Enhances understanding of function behavior via spherical derivatives

Abstract

It is proved that any family of analytic functions with spherical derivative uniformly bounded away from zero ist normal.