102 research outputs found
Integration of information systems on the basis of electronic government
On the basis of E-government conception by integrating the information systems belonging separate state and business organizations, new information services can be established. For instance,"Customs / Domestic production -Trading network - Tax" integration information system. Interested sides (State agencies, business structures and citizens) can be provided by necessary information.
Джафаров Д. M.Интеграция информационных систем на основе электронного правительства.На основании концепции электронного правительства, интегрируя системы, принадлежащие различным государственным и коммерческим организациям, могут быть представлены новые информационные услуги. Например, "Таможня / Внутреннее производство - Торговая сеть - Налоговая". Заинтересованные стороны (Государственные органы, коммерческие структуры и граждане) могут быть обеспечены необходимой информацией
A finite oscillator model related to sl(2|1)
We investigate a new model for the finite one-dimensional quantum oscillator
based upon the Lie superalgebra sl(2|1). In this setting, it is natural to
present the position and momentum operators of the oscillator as odd elements
of the Lie superalgebra. The model involves a parameter p (0<p<1) and an
integer representation label j. In the (2j+1)-dimensional representations W_j
of sl(2|1), the Hamiltonian has the usual equidistant spectrum. The spectrum of
the position operator is discrete and turns out to be of the form
, where k=0,1,...,j. We construct the discrete position wave
functions, which are given in terms of certain Krawtchouk polynomials. These
wave functions have appealing properties, as can already be seen from their
plots. The model is sufficiently simple, in the sense that the corresponding
discrete Fourier transform (relating position wave functions to momentum wave
functions) can be constructed explicitly
The Krawtchouk oscillator model under the deformed symmetry
We define a new algebra, which can formally be considered as a deformed Lie algebra. Then, we present a one-dimensional
quantum oscillator model, of which the wavefunctions of even and odd states are
expressed by Krawtchouk polynomials with fixed , and
. The dynamical symmetry of the model is the newly
introduced algebra. The model itself
gives rise to a finite and discrete spectrum for all physical operators (such
as position and momentum). Among the set of finite oscillator models it is
unique in the sense that any specific limit reducing it to a known oscillator
models does not exist.Comment: Contribution to the 30th International Colloquium on Group
Theoretical Methods in Physics (Ghent, Belgium, 2014). To be published in
Journal of Physics: Conference Serie
The Wigner function of a q-deformed harmonic oscillator model
The phase space representation for a q-deformed model of the quantum harmonic
oscillator is constructed. We have found explicit expressions for both the
Wigner and Husimi distribution functions for the stationary states of the
-oscillator model under consideration. The Wigner function is expressed as a
basic hypergeometric series, related to the Al-Salam-Chihara polynomials. It is
shown that, in the limit case (), both the Wigner and Husimi
distribution functions reduce correctly to their well-known non-relativistic
analogues. Surprisingly, examination of both distribution functions in the
q-deformed model shows that, when , their behaviour in the phase space
is similar to the ground state of the ordinary quantum oscillator, but with a
displacement towards negative values of the momentum. We have also computed the
mean values of the position and momentum using the Wigner function. Unlike the
ordinary case, the mean value of the momentum is not zero and it depends on
and . The ground-state like behaviour of the distribution functions for
excited states in the q-deformed model opens quite new perspectives for further
experimental measurements of quantum systems in the phase space.Comment: 16 pages, 24 EPS figures, uses IOP style LaTeX, some misprints are
correctd and journal-reference is adde
The oscillator model for the Lie superalgebra sh(2|2) and Charlier polynomials
We investigate an algebraic model for the quantum oscillator based upon the
Lie superalgebra sh(2|2), known as the Heisenberg-Weyl superalgebra or "the
algebra of supersymmetric quantum mechanics", and its Fock representation. The
model offers some freedom in the choice of a position and a momentum operator,
leading to a free model parameter gamma. Using the technique of Jacobi
matrices, we determine the spectrum of the position operator, and show that its
wavefunctions are related to Charlier polynomials C_n with parameter gamma^2.
Some properties of these wavefunctions are discussed, as well as some other
properties of the current oscillator model.Comment: Minor changes and some additional references added in version
Discrete series representations for sl(2|1), Meixner polynomials and oscillator models
We explore a model for the one-dimensional quantum oscillator based upon the
Lie superalgebra sl(2|1). For this purpose, a class of discrete series
representations of sl(2|1) is constructed, each representation characterized by
a real number beta>0. In this model, the position and momentum operators of the
oscillator are odd elements of sl(2|1) and their expressions involve an
arbitrary parameter gamma. In each representation, the spectrum of the
Hamiltonian is the same as that of the canonical oscillator. The spectrum of
the momentum operator can be continuous or infinite discrete, depending on the
value of gamma. We determine the position wavefunctions both in the continuous
and discrete case, and discuss their properties. In the discrete case, these
wavefunctions are given in terms of Meixner polynomials. From the embedding
osp(1|2)\subset sl(2|1), it can be seen why the case gamma=1 corresponds to the
paraboson oscillator. Consequently, taking the values (beta,gamma)=(1/2,1) in
the sl(2|1) model yields the canonical oscillator.Comment: (some minor misprints were corrected in this version
Exact solution of the position-dependent effective mass and angular frequency Schr\"odinger equation: harmonic oscillator model with quantized confinement parameter
We present an exact solution of a confined model of the non-relativistic
quantum harmonic oscillator, where the effective mass and the angular frequency
are dependent on the position. The free Hamiltonian of the proposed model has
the form of the BenDaniel--Duke kinetic energy operator. The
position-dependency of the mass and the angular frequency is such that the
homogeneous nature of the harmonic oscillator force constant and hence the
regular harmonic oscillator potential is preserved. As a consequence thereof, a
quantization of the confinement parameter is observed. It is shown that the
discrete energy spectrum of the confined harmonic oscillator with
position-dependent mass and angular frequency is finite, has a non-equidistant
form and depends on the confinement parameter. The wave functions of the
stationary states of the confined oscillator with position-dependent mass and
angular frequency are expressed in terms of the associated Legendre or
Gegenbauer polynomials. In the limit where the confinement parameter tends to
, both the energy spectrum and the wave functions converge to the
well-known equidistant energy spectrum and the wave functions of the stationary
non-relativistic harmonic oscillator expressed in terms of Hermite polynomials.
The position-dependent effective mass and angular frequency also become
constant under this limit
Coherent States and a Path Integral for the Relativistic Linear Singular Oscillator
The SU(1,1) coherent states for a relativistic model of the linear singular
oscillator are considered. The corresponding partition function is evaluated.
The path integral for the transition amplitude between SU(1,1) coherent states
is given. Classical equations of the motion in the generalized curved phase
space are obtained. It is shown that the use of quasiclassical Bohr-Sommerfeld
quantization rule yields the exact expression for the energy spectrum.Comment: 14 pages, 2 figures, Uses RevTeX4 styl
The Wigner distribution function for the one-dimensional parabose oscillator
In the beginning of the 1950's, Wigner introduced a fundamental deformation
from the canonical quantum mechanical harmonic oscillator, which is nowadays
sometimes called a Wigner quantum oscillator or a parabose oscillator. Also, in
quantum mechanics the so-called Wigner distribution is considered to be the
closest quantum analogue of the classical probability distribution over the
phase space. In this article, we consider which definition for such
distribution function could be used in the case of non-canonical quantum
mechanics. We then explicitly compute two different expressions for this
distribution function for the case of the parabose oscillator. Both expressions
turn out to be multiple sums involving (generalized) Laguerre polynomials.
Plots then show that the Wigner distribution function for the ground state of
the parabose oscillator is similar in behaviour to the Wigner distribution
function of the first excited state of the canonical quantum oscillator.Comment: 20 pages, 2 EPS figures, published in Journal of Physics
A relativistic model of the -dimensional singular oscillator
Exactly solvable -dimensional model of the quantum isotropic singular
oscillator in the relativistic configurational -space is proposed. It
is shown that through the simple substitutions the finite-difference equation
for the -dimensional singular oscillator can be reduced to the similar
finite-difference equation for the relativistic isotropic three-dimensional
singular oscillator. We have found the radial wavefunctions and energy spectrum
of the problem and constructed a dynamical symmetry algebra.Comment: 8 pages, accepted for publication in J. Phys.
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