Length Distortion Of Curves Under Meromorphic Univalent Mappings

Bibliographic Details
Title: Length Distortion Of Curves Under Meromorphic Univalent Mappings
Authors: Bhowmik, Bappaditya, Maity, Deblina
Publication Year: 2024
Collection: Mathematics
Subject Terms: Mathematics - Complex Variables, 30C35, 30C20, 30C55
More Details: Let $f$ be a conformal (analytic and univalent) map defined on the open unit disk $\D$ of the complex plane $\IC$ that is continuous on the semi-circle $\partial \D^{+}=\{z\in\IC:|z|=1, {\rm{Im}}\,z>0\}$. The existence of a uniform upper bound for the ratio of the length of the image of the horizontal diameter $(-1,1)$ to the length of the image of $\partial \D^{+}$ under $f$ was proved by Gehring and Hayman. In this article, at first, we generalize this result by introducing a simple pole for $f$ in $\D$ and considering the ratio of the length of the image of the vertical diameter $I=\{z: {\rm{Re}}\,z=0; ~|{\rm{Im}}\,z|<1\}$ to the length of the image of the semi-circle $C'=\{z: |z|=1;~ {\rm{Re}}\,z<0\}$ under such $f$. Finally, we further generalize this result by replacing the vertical diameter $I$ with a hyperbolic geodesic symmetric with respect to the real line, and by replacing $C'$ with the corresponding arc of the unit circle passing through the point $-1$.
Comment: 13 pages, submitted to a journal
Document Type: Working Paper
Access URL: http://arxiv.org/abs/2412.19075
Accession Number: edsarx.2412.19075
Database: arXiv