Перегляд за автором "Ryazanov, V.I."

Сортувати за: Порядок: Результатів:

  • Bojarski, B.V.; Gutlyanskii, V.V.; Ryazanov, V.I. (Український математичний вісник, 2008)
    We study the Beltrami equations ∂f = μ(z)∂f + ν(z)∂f under the assumption that the coefficients μ, ν satisfy the inequality |μ| + |ν| < 1 almost everywhere. Sufficient conditions for the existence of homeomorphic ACL ...
  • Gutlyanskii, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2018)
    We study semilinear partial differential equations in the plane, the linear part of which is written in a divergence form. The main result is given as a factorization theorem. This theorem states that every weak solution ...
  • Gutlyanskii, V.Y.; Nesmelova, O.V.; Ryazanov, V.I. (Український математичний вісник, 2016)
    Assume that Ω is a regular domain in the complex plane C and A(z) is symmetric 2 × 2 matrix with measurable entries, det A = 1 and such that 1/K|ξ|² ≤ 〈A(z)ξ, ξ〉 ≤ K|ξ|², ξ ∊ R², 1 ≤ K < ∞. We study the blow-up problem ...
  • Gutlyanskiĭ, V.Ya.; Ryazanov, V.I.; Yefimushkin, A.S. (Доповіді НАН України, 2017)
    We give a short description of our recent results obtained by a new approach to the boundary-value problems, such as the Dirichlet, Hilbert, Neumann, Poincaré and Riemann problems, for the Beltrami equations and for ...
  • Gutlyanskii, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2018)
    We study semilinear elliptic equations of the form div(A(z)∇u) = f(u) in Ω⊂ C, where A(z) stands for a symmetric 2×2 matrix function with measurable entries, det A =1, and such that 1/ K |ξ|² ≤ 〈A(z)ξ,ξ〉 ≤ K |ξ|², ξ ∈ R², ...
  • Gutlyanskii, V.Ya.; Ryazanov, V.I.; Yakubov, E.; Yefimushkin, A.S. (Доповіді НАН України, 2019)
    We study the Hilbert boundaryvalue problem for the Beltrami equations in the Jordan domains satisfying the quasihyperbolic boundary condition by Gehring—Martio, generally speaking, without the standard (A)condition by ...
  • Gutlyanskii, V.Y.; Ryazanov, V.I. (Український математичний вісник, 2016)
    The survey is devoted to recent advances in nonclassical solutions of the main boundary value problems such as the well–known Dirichlet, Hilbert, Neumann, Poincare and Riemann problems in the plane. Such solutions are ...
  • Gutlyanskiĭ, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2019)
    We study the Dirichlet problem for the semilinear partial differential equations div (A∇u) = f (u) in simply connected domains D of the complex plane C with continuous boundary data. We prove the existence of the weak ...
  • Ryazanov, V.I. (Праці Інституту прикладної математики і механіки НАН України, 2017)
    It is proved that if a harmonic function u on the unit disk D in C has angular limits on a measurable set E of the unit circle, then its conjugate harmonic function v in D also has (finite !) angular limits a.e. on E and ...
  • Gutlyanskii, V.Y.; Ryazanov, V.I.; Yefimushkin, A.S. (Український математичний вісник, 2015)
    Generalized solvability of the classical boundary value problems for analytic and quasiconformal functions in arbitrary Jordan domains with boundary data that are measurable with respect to the logarithmic capacity is ...
  • Gutlyanskii, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Праці Інституту прикладної математики і механіки НАН України, 2017)
    We study the Dirichlet problem for the quasilinear partial differential equations of the form Δu(z) = h(z)·f(u(z)) in the unit disk D ⊂ C with functions h : D → R in the class Lp(D), p > 1, and continuous functions f : R ...
  • Gutlyanskii, V.Ya.; Ryazanov, V.I.; Yakubov, E.; Yefimushkin, A.S. (Доповіді НАН України, 2019)
    We study the Hilbert boundary-value problem for analytic functions in the Jordan domains satisfying the quasi-hyperbolic boundary condition by Gehring—Martio. Assuming that the coefficients of the problem are functions ...
  • Gutlyanskiĭ, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2018)
    We study the Dirichlet problem for quasilinear partial differential equations of the form Δu(z) = h(z)f(u(z)) in the unit disk D ⊂ C with continuous boundary data. Here, the function h : D→R belongs to the class L^p(D), ...
  • Ryazanov, V.I.; Srebro, U.; Yakubov, E. (Український математичний журнал, 2006)
    We study ring homeomorphisms and, on this basis, obtain a series of theorems on existence of the so-called ring solutions for degenerate Beltrami equations. A general statement on the existence of solutions for the ...
  • Ryazanov, V.I.; Volkov, S.V. (Доповіді НАН України, 2017)
    We prove criteria for the homeomorphic extension of mappings with finite distortion between the domains on Riemann surfaces to the boundary by prime Carathéodory ends.
  • Gutlyanskiĭ, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2017)
    We consider generalizations of the Bieberbach equation with nonlinear right parts, which makes it possible to study many problems of mathematical physics in inhomogeneous and anisotropic media with smooth characteristics. ...
  • Kovtonyuk, D.A.; Petkov, I.V.; Ryazanov, V.I. (Труды Института прикладной математики и механики, 2010)
    In this article it is shown that each homeomorphic W1,1loc solution to the Beltrami equation ∂f = μ∂f is the so-called lower Q-homeomorphism with Q(z) = Kμ(z) where Kμ(z) is dilatation quotient of this equation. It is ...
  • Gutlyanskii, V.Y.; Ryazanov, V.I.; Yakubov, E. (Український математичний вісник, 2015)
    We first study the boundary behavior of ring Q-homeomorphisms in terms of Carath´eodory’s prime ends and then give criteria to the solvability of the Dirichlet problem for the degenerate Beltrami equation ∂f = μ∂f in ...
  • Bojarski, B.V.; Gutlyanskiĭ, V.Ya.; Ryazanov, V.I. (Доповіді НАН України, 2013)
  • Gutlyanskii, V.Ya.; Ryazanov, V.I.; Yakubov, E. (Доповіді НАН України, 2015)
    The Dirichlet problem for the degenerate Beltrami equations in arbitrary finitely connected domains is studied. In terms of the tangent dilatations, a series of criteria for the existence of regular solutions in arbitrary ...