3 citations · 9 across the 7 of their papers we have counts for
7 papers
Completeness property of one-dimensional perturbations of normal and spectral operators generated by first order systems
Anton A. Lunyov, Mark M. Malamud
The paper is concerned with completeness property of rank one perturbations of unperturbed operators generated by special boundary value problems (BVP) for the following $2 \times…
Krein extension of a differential operator of even order
Yaroslav Granovskyi, Leonid Oridoroga
We describe the Krein extension of minimal operator associated with the expression A:=(-1)^n*d^(2n)/dx^(2n) on a finite interval (a,b) in terms of boundary conditions. All non-nega…
Radial positive definite functions and Schoenberg matrices with negative eigenvalues
L. Golinskii, M. Malamud, L. Oridoroga
The main object under consideration is a class of radial positive definite functions on which do not admit \emph{radial positive definite continuation…
Schoenberg matrices of radial positive definite functions and Riesz sequences in
L. Golinskii, M. Malamud, L. Oridoroga
Given a function on the positive half-line and a sequence (finite or infinite) of points in , we define and study matrices $\kS_X(f)=\|f(|x_i-x…
On the completeness of the system of root vectors for first-order systems
M. M. Malamud, L. L. Oridoroga
The paper is concerned with the completeness problem of root functions of general boundary value problems for first order systems of ordinary differential equations. Namely, we int…
On the Negative Spectrum of One-Dimensional Schrödinger Operators with Point Interactions
Nataly Goloschapova, Leonid Oridoroga
We investigate negative spectra of 1--D Schrödinger operators with - and -interactions on a discrete set in the framework of a new approach. Namely, using technique of bound…
Theorem of completeness for a Dirac-type operator with generalized -depending boundary conditions
Seppo Hassi, Leonid Oridoroga
A completeness theorem is proved involving a system of integro-differential equations with some -depending boundary conditions. Also some sufficient conditions for the root func…