English

The spherical metric and univalent harmonic mappings

Complex Variables 2018-07-17 v1

Abstract

Let f=h+gf=h+\overline{g} be a harmonic univalent map in the unit disk D\mathbb{D}, where hh and gg are analytic. We obtain an improved estimate for the second coefficient of hh. This indeed is the first qualitative improvement after the appearance of the papers by Clunie and Sheil-Small in 1984, and by Sheil-Small in 1990. Also, when the sup-norm of the dilatation is less than 11, it is shown that the spherical area of the covering surface of hh is dominated by the spherical area of the covering surface of f.f.

Keywords

Cite

@article{arxiv.1807.05654,
  title  = {The spherical metric and univalent harmonic mappings},
  author = {Yusuf Abu Muhanna and Rosihan M. Ali and Saminathan Ponnusamy},
  journal= {arXiv preprint arXiv:1807.05654},
  year   = {2018}
}

Comments

12 pages; An earlier version of it is already available online from Monatshefte fuer Mathematik

R2 v1 2026-06-23T03:02:08.575Z