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# Green‘s Function and Poisson Integral in a Circle Disk for Strongly Elliptic Systems with Constant Coefficients

 Authors: Bagapsh A.O. Published: 22.11.2017 Published in issue: #6(75)/2017 DOI: 10.18698/1812-3368-2017-6-4-18 Category: Mathematics | Chapter: Substantial Analysis, Complex and Functional Analysis Keywords: elliptic systems, strong ellipticity, Dirichlet problem, Poisson integral, Green's function, skew-symmetric systems, Lame system

The paper deals with Dirichlet problem for a homogeneous strongly elliptic second-order system with constant coefficients, in other words, for a partial differential equation of the following kind Lτ,σf = 0 where f is a complex-valued function, and Lτ,σ= (∂∂τ∂2)I+σ(τ∂∂+∂2)C. Here δδ are Cauchy --- Riemann operators; I is an identity operator; C:z--- z̅ is a complex conjugation operator; τ,σ are such parameters, that τσ ∈ (--1,1). For such systems, integral formulas of the Poisson type, Green's function and solutions of Dirichlet problem in a circle and an ellipse of a special form are obtained. The Lτ,σ operator is a perturbation of Laplace operator Δ, and the Dirichlet problem solution for the equation Lτ,σf = 0 is obtained as a sum of a series in powers of the parameter σ. Functions that are coefficients of the corresponding series can be found by solving the "recurrent" sequence of Dirichlet problems for the ordinary Laplace and Poisson equations.

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