Higher-Order Schippers-Schwarzian Derivatives for Non-Circular Starlike Functions

Abstract

We find sharp upper bounds for the initial higher-order Schippers-Schwarzian derivatives ${\sigma }_3(f)(0)$ and ${\sigma }_4(f)(0)$ for several subclasses of univalent and starlike functions in the unit disk. The functions in these classes are defined by subordination to domains bounded by an exponential-sine curve, a cardioid, or a petal-shaped curve. We determine the sharp bounds and find the corresponding extremal functions for each invariant in these subclasses. As an application, we also obtain sharp bounds for the initial Grunsky coefficients ${\omega }_{1,1}$ and ${\omega }_{1,2}$.