Locally one-to-one harmonic functions with starlike analytic part

Abstract

Let $L_H$ denote the set of all normalized locally one-to-one and sense-preserving harmonic functions in the unit disc $\Delta$. It is well-known that every complex-valued harmonic function in the unit disc $\Delta$ can be uniquely represented as $f=h+\overline{g}$, where $h$ and $g$ are analytic in $\Delta$. In particular the decomposition formula holds true for functions of the class $L_H$. For a fixed analytic function $h$, an interesting problem arises - to describe all functions $g$, such that $f$ belongs to $L_H$. The case when $f\in L_H$ and $h$ is the identity mapping was considered [2]. More general results are given in [3], where $f\in L_H$ and letting $h$ to be a convex analytic mapping. The focus of our present research is to characterize the set of all functions $f\in L_H$ having starlike analytic part $h$. In this paper, we provide coefficient, distortion and growth estimates of $g$. We also give growth and Jacobian estimates of $f$.

6 pages