English

Three Value Ranges for Symmetric Self-mappings

Complex Variables 2016-07-01 v3

Abstract

Let D\mathbb D be the unit disc and z0D.z_0\in\mathbb D. We determine the value range {f(z0)fR}\{f(z_0)\,|\, f\in \mathcal{R}^\geq\}, where R\mathcal{R}^\geq is the set of holomorphic functions f:DDf:\mathbb D\to\mathbb D with f(0)=0f(0)=0 and f(0)0f'(0)\geq0 that have only real coefficients in their power series expansion around 00, and the smaller set \{f(z_0)\,|\, f\in \mathcal{R}^\geq, \text{f is typically real}\}. Furthermore, we describe a third value range {f(z0)fI}\{ f(z_0) \,|\, f \in \mathcal{I}\}, where I\mathcal{I} consists of all univalent self-mappings of the upper half-plane H\mathbb{H} with hydrodynamical normalization which are symmetric with respect to the imaginary axis.

Keywords

Cite

@article{arxiv.1602.05058,
  title  = {Three Value Ranges for Symmetric Self-mappings},
  author = {Julia Koch and Sebastian Schleißinger},
  journal= {arXiv preprint arXiv:1602.05058},
  year   = {2016}
}
R2 v1 2026-06-22T12:51:23.195Z