%0 Journal Article
%T On a theorem of Lindel f
%A Vladimir Gutlyanskii
%A Olli Martio
%A Vladimir Ryazanov
%J Annales UMCS, Mathematica
%D 2011
%I 
%R 10.2478/v10062-011-0012-7
%X We give a quasiconformal version of the proof for the classical Lindel f theorem: Let f map the unit disk D conformally onto the inner domain of a Jordan curve C. Then C is smooth if and only if arh f'(z) has a continuous extension to D. Our proof does not use the Poisson integral representation of harmonic functions in the unit disk.
%K Lindel f theorem
%K infinitesimal geometry
%K continuous extension to the boundary
%K differentiability at the boundary
%K conformal and quaisconformal mappings
%U http://versita.metapress.com/content/c3653553p7r0014n/?p=9e685f8f8e3c43feac8c2f72770a2544&pi=4