学术文献库

We give here results on the existence of nonclassical solutions of the Hilbert boundary value problem in terms of the so-called angular limits (along nontangent curves to the boundary) for Beltrami equations with sources in Jordan domains satisfying the quasihyperbolic boundary condition by Gehring-Martio, generally speaking, without $(A)-$condition by Ladyzhenskaya-Ural'tseva and, in particular, without the known outer cone condition that were standard for boundary value problems in the PDE theory. Assuming that the coefficients of the problem are functions of countable bounded variation and the boundary data are measurable with respect to the logarithmic capacity, we prove the existence of locally Hölder continuous solutions of the problem. Moreover, we prove similar results on the Hilbert boundary value problem with its arbitrary measurable boundary data as well as coefficients in finitely connected Jordan domains along the so-called general Bagemihl-Seidel systems of Jordan arcs to their boundaries. In the same terms, we formulate theorems on the existence of regular solutions of the known Riemann boundary value problems, including nonlinear, with arbitrary measurable coefficients for the nonhomogeneous Beltrami equations. We give also the representation of obtained solutions through the so-called generalized analytic functions with sources. Finally, we formulate similar results on Poincare and Neumann problems for the Poisson type equations that are main in hydromechanics (mechanics of incompressible fluids) in anisotropic and inhomogeneous media. We give here the representation of their solutions through the so-called generalized harmonic functions with sources that describe the corresponding physical processes in iso\-tro\-pic and homogeneous media.