373 research outputs found
On a Generalized Oscillator: Invariance Algebra and Interbasis Expansions
This article deals with a quantum-mechanical system which generalizes the
ordinary isotropic harmonic oscillator system. We give the coefficients
connecting the polar and Cartesian bases for D=2 and the coefficients
connecting the Cartesian and cylindrical bases as well as the cylindrical and
spherical bases for D=3. These interbasis expansion coefficients are found to
be analytic continuations to real values of their arguments of the
Clebsch-Gordan coefficients for the group SU(2). For D=2, the superintegrable
character for the generalized oscillator system is investigated from the points
of view of a quadratic invariance algebra.Comment: 13 pages, Latex file. Submitted for publication to Yadernaya Fizik
The Cosmic Microwave Background and Inflation Parameters
We review the currrent cosmic parameter determinations of relevance to
inflation using the WMAP-1year, Boomerang, CBI, Acbar and other CMB data. The
basic steps in the pipelines which determine the bandpowers from the raw data
from which these estimations are made are summarized. We forecast how the
precision is likely to improve with more years of WMAP in combination with
future ground-based experiments and with Planck. We address whether the current
data indicates strong breaking from uniform acceleration through the relatively
small region of the inflaton potential that the CMB probes, manifest in the
much-discussed running spectral index or in even more radical braking/breaking
scenarios. Although some weak ``anomalies'' appear in the current data, the
statistical case is not there. However increased precision, at the high
multipole end and with polarization measurements, will significantly curtail
current freedom.Comment: 24 pages, 10 figures, 2 tables, Int. J. Theor. Phys. 2004, ed. E.
Verdaguer, "Peyresq Physics 8", "The Early Universe: Confronting theory with
observations" (June 21-27, 2003
Coulomb-oscillator duality in spaces of constant curvature
In this paper we construct generalizations to spheres of the well known
Levi-Civita, Kustaanheimo-Steifel and Hurwitz regularizing transformations in
Euclidean spaces of dimensions 2, 3 and 5. The corresponding classical and
quantum mechanical analogues of the Kepler-Coulomb problem on these spheres are
discussed.Comment: 33 pages, LaTeX fil
Non Gaussian extrema counts for CMB maps
In the context of the geometrical analysis of weakly non Gaussian CMB maps,
the 2D differential extrema counts as functions of the excursion set threshold
is derived from the full moments expansion of the joint probability
distribution of an isotropic random field, its gradient and invariants of the
Hessian. Analytic expressions for these counts are given to second order in the
non Gaussian correction, while a Monte Carlo method to compute them to
arbitrary order is presented. Matching count statistics to these estimators is
illustrated on fiducial non-Gaussian "Planck" data.Comment: 4 pages, 1 figur
ФАКТОРЫ, ВЛИЯЮЩИЕ НА РАСПРОСТРАНЕНИЕ И ПРИНЯТИЕ ИННОВАЦИЙ В СФЕРЕ ПЛАТЕЖНЫХ ТЕХНОЛОГИЙ
Non-cash payments provide a small part of total payment volume, but the usage of innovative products in named area is growing quite rapidly. The present study attempts to identify the factors determining consumers’ acceptance of payment innovation with the aim of developing a conceptual model of payment services acceptance. A research model that reflects economic, technological and socio-demographic factors are all important determinants for payment services adoption and use. Besides, there are specific correlation between them. To simulate the behavior of the consumer it was due to use parameters that reflect the actual level of awareness of innovation, the intention to use and real use of innovation. The result was the conceptual model developed in this research that focuses on factors determining consumers’ acceptance of payment services and their statement.Безналичные платежные инструменты обеспечивают пока незначительную часть платежей, но использование инновационных продуктов в этой сфере растет довольно высокими темпами. Проанализированы факторы, влияющие на распространение и принятие инноваций в платежной сфере, в целях разработки концептуальной модели процесса принятия данного вида инноваций. В результате были выявлены экономико-технологические и социально-демографические факторы, оказывающие наибольшее влияние на рассматриваемый процесс, а также специфические зависимости между ними. Для моделирования поведения потребителя было предложено использовать параметры, отражающие фактический уровень информированности об инновации, намерения использовать инновацию и использования инновации. В результате была построена концептуальная модель, учитывающая факторы, определяющие принятие инноваций в платежной сфере и состояние агента
Velocity Modification of Power Spectrum from Absorbing Medium
Quantitative description of the statistics of intensity fluctuations within
spectral line data cubes introduced in our earlier work is extended to the
absorbing media. A possibility of extracting 3D velocity and density statistics
from both integrated line intensity as well as from the individual channel maps
is analyzed. We find that absorption enables the velocity effects to be seen
even if the spectral line is integrated over frequencies. This regime that is
frequently employed in observations is characterized by a non-trivial relation
between the spectral index of velocities and the spectral index of intensity
fluctuations. For instance when density is dominated by fluctuations at large
scales, i.e. when correlations scale as r^{-\gamma}, \gamma<0, the intensity
fluctuations exhibit a universal spectrum of fluctuations ~K^{-3} over a range
of scales. When small scale fluctuations of density contain most of the energy,
i.e. when correlations scale as r^{-\gamma}, \gamma>0, the resulting spectrum
of the integrated lines depends on the scaling of the underlying density and
scales as K^{-3+\gamma}. We show that if we take the spectral line slices that
are sufficiently thin we recover our earlier results for thin slice data
without absorption. As the result we extend the Velocity Channel Analysis (VCA)
technique to optically thick lines enabling studies of turbulence in molecular
clouds. In addition, the developed mathematical machinery enables a
quantitative approach to solving other problems that involved statistical
description of turbulence within emitting and absorbing gas.Comment: 51 page, 3 figures. Accepted to Astrophysical Journa
Quantum Systems with Hidden Symmetry. Interbasis Expansions
This monograph is the English version of the book "Quantum systems with
hidden symmetry. Interbasis expansions" published in 2006 by the publishing
house FIZMATLIT (Moscow) in Russian. When compiling this version of the book,
typos and inaccuracies noted since the release of the Russian edition have been
corrected
- …