Riyaziyyat

1

Spectral analysis of the indefinite non-self-adjoint Sturm–Liouville operator

Publication date: September 2024
Authors: Efendiev Rakib,  Gasimov, Yusif

Abstract

The study investigates the inverse scattering problem for the Schrodinger operator with complex potentials, considering indefinite discontinuous coefficients on the axis. Using the integral representation of the Jost solutions on the real and imaginary axes, solved the direct scattering problem. An additional study of the operator's spectrum was conducted, scattering data was introduced, and the eigenfunction expansion was obtained. Integral equations derived play a crucial role in solving the inverse problem and finally prove the uniqueness theorem for the solution. © 2024

Author keywords: Complex potentials; Indefinite discontinuous coefficients; Inverse scattering problem; Sturm–Liouville operator

Investigation of The Resolvent Kernel of a Higher Order Differential Equation With Normal Operator Coefficients On The Semi-Axis

Publication date: July 2024
Authors: Orudzhev Hamzaga D.,  Shahbazova, Gahire L.

Abstract

Green function of a 2n-th order differential equation with normal coefficients on the half-axis is studied. We first consider the Green function of our equation with “frozen” coefficients. Using Levi’s method, we obtain a Fredholm-type integral equation for the Green function of our problem, whose kernel is a Green function of a problem with constant coefficients. We prove an existence and uniqueness theorem for this integral equation in some Banach spaces of operator-valued functions. The main result of this paper is a theorem stating that the solution of the obtained integral equation is a Green function of our problem. © 2010 AZJM All rights reserved.

Author keywords: Banach spaces; eigenfunctions; eigenvalues; Green function; Hilbert spaces; integral equation; operator; operator-differential equations; resolvent; spectrum