3,758 research outputs found
Projector operators for the no-core shell model
Projection operators for the use within ab initio no-core shell model, are
suggested.Comment: 3 page
Interaction of Radiation and a Relativistic Electron in Motion in a Constant Magnetic Field
The work examines the effect of multiple photon emission on the quantum
mechanical state of an electron emitting synchrotron radiation and on the
intensity of that radiation. Calculations are done with the variant of
perturbation theory based on the use of extended coherent states. A general
formula is derived for the number of emitted photons, which allows for taking
into account their mutual interaction. A model problem is used to demonstrate
the absence of the infrared catastrophe in the modified perturbation theory.
Finally, the electron density matrix is calculated, and the analysis of this
matrix makes it possible to conclude that the degree of the elecron's spatial
localization increases with the passage of time if the electron is being
accelerated.Comment: 29 pages, no figure
Algebraic Model for scattering in three-s-cluster systems. I. Theoretical Background
A framework to calculate two-particle matrix elements for fully
antisymmetrized three-cluster configurations is presented. The theory is
developed for a scattering situation described in terms of the Algebraic Model.
This means that the nuclear many-particle state and its asymptotic behaviour
are expanded in terms of oscillator states of the intra-cluster coordinates.
The Generating Function technique is used to optimize the calculation of matrix
elements. In order to derive the dynamical equations, a multichannel version of
the Algebraic Model is presented.Comment: 20 pages, 1 postscript figure, submitted to Phys. Rev.
Age features of O2 mass transfer regimes in adolescents’ body at rest
The results of complex studies of the quantitative relationship between the stage-by-stage mass transfer of O2 and the efficiency of cardiorespiratory system functioning in relation to its consumption in adolescents’ body under conditions of relative rest are presented.
The results obtained show that in adolescents, the modes of mass transfer of O2 in the body and the nature of the respiratory and circulatory systems functioning in relation to its consumption have a number of age-related differences compared with adult men. So, in adolescents, the external respiration system at rest functions less economically than in adults. Each liter of O2 consumed by adolescents is extracted from almost 3 liters more than in adults the amount of air ventilated per minute through the lungs. The volumetric indicators of blood circulation are also higher in adolescents, which may indicate the influence of neuro-humoral rearrangements in the body during the pubertal period. The coefficient of oxygen utilization by tissues from arterial blood in adolescents turned out to be significantly higher, which may characterize a higher tension of tissue metabolic processes
Nucleon-nucleon interaction in the -matrix inverse scattering approach and few-nucleon systems
The nucleon-nucleon interaction is constructed by means of the -matrix
version of inverse scattering theory. Ambiguities of the interaction are
eliminated by postulating tridiagonal and quasi-tridiagonal forms of the
potential matrix in the oscillator basis in uncoupled and coupled waves,
respectively. The obtained interaction is very accurate in reproducing the
scattering data and deuteron properties. The interaction is used in the no-core
shell model calculations of H and He nuclei. The resulting binding
energies of H and He are very close to experimental values.Comment: Text is revised, new figures and references adde
Convex ordering and quantification of quantumness
The characterization of physical systems requires a comprehensive
understanding of quantum effects. One aspect is a proper quantification of the
strength of such quantum phenomena. Here, a general convex ordering of quantum
states will be introduced which is based on the algebraic definition of
classical states. This definition resolves the ambiguity of the quantumness
quantification using topological distance measures. Classical operations on
quantum states will be considered to further generalize the ordering
prescription. Our technique can be used for a natural and unambiguous
quantification of general quantum properties whose classical reference has a
convex structure. We apply this method to typical scenarios in quantum optics
and quantum information theory to study measures which are based on the
fundamental quantum superposition principle.Comment: 9 pages, 2 figures, revised version; published in special issue "150
years of Margarita and Vladimir Man'ko
Fractal-like aggregates: Relation between morphology and physical properties
A number of modern technological applications require a detailed
calculation of the physical properties of aggregated aerosol particles. For example, in probing soot aerosols by the method called
laser-induced incandescence (LII), the soot clusters are suddenly
heated by a short, powerful laser pulse and then cool down to the
temperature of the carrier gas. LII sizing is based on rigorous calculation of the soot aggregate heat-up and cooling and involves
prediction of laser light absorption and energy and mass transfer between aggregated particles and the ambient gas. This paper
describes results of numerical simulations of the mass or energy
transfer between the gas and fractal-like aggregates of N spherical
particles in either the free-molecular or continuum regime, as well
as the light scattering properties of random fractal-like aggregates,
based on Rayleigh–Debye–Gans (RDG) theory. The aggregate geometries are generated numerically using specially developed algorithms allowing “tuning” of the fractal dimension and prefactor
values. Our results are presented in the form of easily applicable
scaling laws, with special attention paid to relations between the
aggregate gyration radius and the effective radius describing various transport processes between the aggregates and the carrier gas
Supersymmetric reduced models with a symmetry based on Filippov algebra
Generalizations of the reduced model of super Yang-Mills theory obtained by
replacing the Lie algebra structure to Filippov -algebra structures are
studied. Conditions for the reduced model actions to be supersymmetric are
examined. These models are related with what we call \{cal N}_{min}=2 super
-brane actions.Comment: v3: In the previous versions we overlooked that Eq.(3.9) holds more
generally, and missed some supersymmetric actions. Those are now included and
modifications including a slight change in the title were made accordingly.
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