A Limit-Point Criterion for Separated Dirac Operators and a Little Known Result on Riccati's Equation.
A new approach to inverse spectral theory. I: Fundamental formalism.
A new approach to inverse spectral theory. II: General real potentials and the connection to the spectral measure.
A new approach to Young measure theory, relaxation and convergence in energy
A study of an operator arising in the theory of circular plates
The operator , , , is shown to be essentially self-adjoint, positive definite with a compact resolvent. The conditions on (in fact, on a general symmetric operator) are given so as to justify the application of the Fourier method for solving the problems of the types and , respectively.
Almost periodic Sturm-Liouville operators with Cantor homogeneous spectrum.
An extension of Krein's inverse spectral theorem to strings with nonreflecting left boundaries
An inverse problem for Sturm-Liouville operators on the half-line having Bessel-type singularity in an interior point
We study the inverse problem of recovering Sturm-Liouville operators on the half-line with a Bessel-type singularity inside the interval from the given Weyl function. The corresponding uniqueness theorem is proved, a constructive procedure for the solution of the inverse problem is provided, also necessary and sufficient conditions for the solvability of the inverse problem are obtained.
Boundary Data Maps for Schrödinger Operators on a Compact Interval
We provide a systematic study of boundary data maps, that is, 2 × 2 matrix-valued Dirichlet-to-Neumann and more generally, Robin-to-Robin maps, associated with one-dimensional Schrödinger operators on a compact interval [0, R] with separated boundary conditions at 0 and R. Most of our results are formulated in the non-self-adjoint context. Our principal results include explicit representations of these boundary data maps in terms of the resolvent...
Das Randwertproblem für eine Klasse singulärer gewöhnlicher Differentialausdrücke.
Das Randwertproblem für eine Klasse singulärer gewöhnlicher Differentialausdrücke. (Short Communication).
Funktionalgleichungen in reellen Vektorräumen und verallgemeinerte Cauchy-Riemannsche Differentialgleichungen, speziell die Weylsche Gleichung des Neutrinos.
Funktionalgleichungen in reellen Verktorräumen und verallgemeinerte Cauchy-Riemannsche Differentialgleichungen, speziell die Weylsche Gleichung des Neutrinos. (Short Communication).
Greensche Matrix und die Formel von Titchmarsh-Kodaira für singuläre S-hermitesche Eigenwertprobleme.
KdV Equation in the Quarter–Plane: Evolution of the Weyl Functions and Unbounded Solutions
The matrix KdV equation with a negative dispersion term is considered in the right upper quarter–plane. The evolution law is derived for the Weyl function of a corresponding auxiliary linear system. Using the low energy asymptotics of the Weyl functions, the unboundedness of solutions is obtained for some classes of the initial–boundary conditions.
Limit Circle Results for Second Order Equations.
Linksdefinite singuläre kanonische Eigenwertprobleme. I.
Linksdefinite singuläre kanonische Eigenwertprobleme. II.
Lp-Perturbations of Second Order Linear Differential Equations.
Multiple positive solutions of the singular boundary value problem for second-order impulsive differential equations on the half-line.