4 citations · 15 across the 21 of their papers we have counts for
24 papers
On the similarity of boundary triples for dual pairs
Rytis Jursenas
The Weyl family of a dual pair of operators in a Krein space determines a minimal boundary triple uniquely up to similarity; if , a necessary and sufficient c…
On a boundary pair of a dissipative operator
Rytis Jursenas
The aim of this brief note is to demonstrate that the boundary pair of a dissipative operator is determined by the unitary boundary pair of its symmetric part.
Locus of non-real eigenvalues of a class of linear relations in a Krein space
Rytis Jursenas
It is a classical result that, if a maximal symmetric operator in a Krein space has the property $\mathcal{H}^-\subseteq\mathca…
On the similarity of boundary triples of symmetric operators in Krein spaces
Rytis Jursenas
It is a classical result that the Weyl function of a simple symmetric operator in a Hilbert space determines a boundary triple uniquely up to unitary equivalence. We generalize thi…
On necessary and sufficient conditions relating the adjoint of a column to a row of linear relations
Rytis Jursenas
A row and a column of two linear relations in Hilbert spaces are presented respectively as a sum and an intersection of two linear relations. As an application, necessary and suffi…
The A-model with mutually equal model parameters can lead to a Hilbert space model
Rytis Jursenas
It is known that the A-model for higher order singular perturbations can be considered as a Hilbert space model if the model parameters are mutually distinct, and that it is necess…
Weyl families of transformed boundary pairs
R. Jursenas
Let be an isometric boundary pair associated with a closed symmetric linear relation in a Krein space . Let be the Weyl family correspond…
On some extensions of the A-model
Rytis Jursenas
The A-model for finite rank singular perturbations of class , , is considered from the perspective of boundary…
Weyl families of essentially unitary pairs
Rytis Jursenas
It is known that the Weyl families corresponding to unitary boundary pairs belong to the class of Nevanlinna families. Here we…
The peak model for finite rank supersingular perturbations
Rytis Jursenas
In its original form the peak model for rank one supersingular perturbations of class or higher of a nonnegative self-adjoint operator requires that the Gram ma…
Irreducible tensor form for the AME coupling
Rytis Jursenas
Using the multipole expansion of electromagnetic (EM) field, we present the angular magnetoelectric (AME) coupling in irreducible tensor form. We evaluate the matrix elements when…
Computation of unitary group for the Rashba spin-orbit coupled operator, with application to point-interactions
Rytis Jursenas
We compute an explicit formula for the one-parameter unitary group of the single-particle Rashba spin-orbit coupled operator in dimension three. As an application, we derive the fo…
Direct integral description of angulon
Rytis Jursenas
We propose a representation of angulon in which the angulon operator is decomposable relative to the field of Hilbert spaces over the probability measure space, and the probability…
A model for reducing the angulon operator
Rytis Jursenas, Mikhail Lemeshko
We propose a mathematical model for the recently introduced angulon. In our formulation, the angulon operator is decomposable relative to the field of Hilbert spaces over the proba…
Spectrum of a family of spin-orbit coupled Hamiltonians with singular perturbation
Rytis Jursenas
The present study is the first such attempt to examine rigorously and comprehensively the spectral properties of a three-dimensional ultracold atom when both the spin-orbit interac…
Series expansion for the Fourier transform of a rational function in three dimensions
Rytis Jursenas
In Rashba-Dresselhaus spin-orbit coupled systems, the calculation of Green's function requires the knowledge of the inverse Fourier transform of rational function , wher…
A note on the spectrum of a two-particle Rashba Hamiltonian
Rytis Jursenas
In a series of recent papers it was shown that, when the attractive s-wave interaction is dominant, the spin-orbit coupled fermions form a bound state. Attributed to a convenient m…
Bound states of the spin-orbit coupled ultracold atom in a one-dimensional short-range potential
Rytis Jursenas, Julius Ruseckas
We solve the bound state problem for the Hamiltonian with the spin-orbit and the Raman coupling included. The Hamiltonian is perturbed by a one-dimensional short-range potential V…
On the definite integral of two confluent hypergeometric functions related to the Kampé de Fériet double series
Rytis Jursenas
The Kampé de Fériet double series is studied through the solution to the associated first-order nonhomogeneous differential equation. It is shown that the integ…
On the three-body Schrödinger equation with decaying potentials
Rytis Jursenas
The three-body Schrödinger operator in the space of square integrable functions is found to be a certain extension of operators which generate the exponential unitary group contain…
Application of symbolic programming for atomic many-body theory
Rytis Jursenas, Gintaras Merkelis
In the present paper by using Mathematica system a symbolic programming method for generation of the expressions of the expansion terms of atomic stationary perturbation theory (PT…
Coupled tensorial form for atomic relativistic two-particle operator given in second quantization representation
Rytis Jursenas, Gintaras Merkelis
General formulas of the two-electron operator representing either atomic or effective interactions are given in a coupled tensorial form in relativistic approximation. The alternat…
Irreducible tensor form of three-particle operator for open-shell atoms
Rytis Jursenas, Gintaras Merkelis
The three-particle operator in a second quantized form is studied. The operator is transformed into irreducible tensor form. Possible coupling schemes, distinguished by the classes…
The transformation of irreducible tensor operators under spherical functions
R. Jursenas, G. Merkelis
The irreducible tensor operators and their tensor products employing Racah algebra are studied. Transformation procedure of the coordinate system operators act on are introduced. T…