In this study we deal with the nonlinear Riemann--Hilbert problem (in short (RHP)) for generalized analytic functions in multiply connected domains. Using a similarity principle for multiply connected domains (presented here for the first time), we reduce the nonlinear RHP for generalized analytic functions to a corresponding nonlinear RHP for holomorphic functions with Hölder continuous boundary data. Then the Newton--Kantorovič method combined with a continuation procedure as well as a new existence theorem for holomorphic solutions, which is
based on topological degree arguments, leads to existence of at least two topologically different generalized analytic functions solving the nonlinear RHP.
@article{1246454028,
author = {Efendiev, Messoud A. and Wendland, Wolfgang L.},
title = {Nonlinear Riemann-Hilbert Problems for Generalized Analytic Functions},
journal = {Funct. Approx. Comment. Math.},
volume = {40},
number = {1},
year = {2009},
pages = { 185-208},
language = {en},
url = {http://dml.mathdoc.fr/item/1246454028}
}
Efendiev, Messoud A.; Wendland, Wolfgang L. Nonlinear Riemann-Hilbert Problems for Generalized Analytic Functions. Funct. Approx. Comment. Math., Tome 40 (2009) no. 1, pp. 185-208. http://gdmltest.u-ga.fr/item/1246454028/