Geometrical properties of nonlinear maps and their application. II: Nonlinear Riemann--Hilbert problems with closed boundary data for multiply connected domains
The topological degree of quasiruled Fredholm maps on quasicylindrical domains developed by authors in Part I [J.~Math.\ Anal.\ Appl.\ 329, No.~1, 383--391 (2007; Zbl 1108.47052), see the preceding review] is used to prove the existence of at least two homotopically different solutions of classical nonlinear Riemann--Hilbert problems with closed boundary data for multiply connected domains.
scientific article; zbMATH DE number 5129657