Displaying similar documents to “Uniform convergence of the spectral expansion for a differential operator with periodic matrix coefficients.”

On the basis property of the root functions of differential operators with matrix coefficients

Oktay Veliev (2011)

Open Mathematics

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We obtain asymptotic formulas for eigenvalues and eigenfunctions of the operator generated by a system of ordinary differential equations with summable coefficients and periodic or antiperiodic boundary conditions. Then using these asymptotic formulas, we find necessary and sufficient conditions on the coefficients for which the system of eigenfunctions and associated functions of the operator under consideration forms a Riesz basis.

Discrete spectrum and principal functions of non-selfadjoint differential operator

Gülen Başcanbaz Tunca, Elgiz Bairamov (1999)

Czechoslovak Mathematical Journal

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In this article, we consider the operator L defined by the differential expression ( y ) = - y ' ' + q ( x ) y , - < x < in L 2 ( - , ) , where q is a complex valued function. Discussing the spectrum, we prove that L has a finite number of eigenvalues and spectral singularities, if the condition sup - < x < exp ϵ | x | | q ( x ) | < , ϵ > 0 holds. Later we investigate the properties of the principal functions corresponding to the eigenvalues and the spectral singularities.

A Sturm-Liouville problem with spectral and large parameters in boundary conditions and the associated Cauchy problem

Jamel Ben Amara (2011)

Colloquium Mathematicae

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We study a Sturm-Liouville problem containing a spectral parameter in the boundary conditions. We associate to this problem a self-adjoint operator in a Pontryagin space Π₁. Using this operator-theoretic formulation and analytic methods, we study the asymptotic behavior of the eigenvalues under the variation of a large physical parameter in the boundary conditions. The spectral analysis is applied to investigate the well-posedness and stability of the wave equation of a string. ...

Spectral properties of some regular boundary value problems for fourth order differential operators

Nazim Kerimov, Ufuk Kaya (2013)

Open Mathematics

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In this paper we consider the problem y i v + p 2 ( x ) y ' ' + p 1 ( x ) y ' + p 0 ( x ) y = λ y , 0 < x < 1 , y ( s ) ( 1 ) - ( - 1 ) σ y ( s ) ( 0 ) + l = 0 s - 1 α s , l y ( l ) ( 0 ) = 0 , s = 1 , 2 , 3 , y ( 1 ) - ( - 1 ) σ y ( 0 ) = 0 , where λ is a spectral parameter; p j (x) ∈ L 1(0, 1), j = 0, 1, 2, are complex-valued functions; α s;l, s = 1, 2, 3, l = 0 , s - 1 ¯ , are arbitrary complex constants; and σ = 0, 1. The boundary conditions of this problem are regular, but not strongly regular. Asymptotic formulae for eigenvalues and eigenfunctions of the considered boundary value problem are established in the case α 3,2 + α 1,0 ≠ α 2,1. It is proved that the system of root functions of this...