14,580 research outputs found
d-Dimensional generalization of the point canonical transformation for a quantum particle with position-dependent mass
The d-dimensional generalization of the point canonical transformation for a
quantum particle endowed with a position-dependent mass in Schrodinger equation
is described. Illustrative examples including; the harmonic oscillator,
Coulomb, spiked harmonic, Kratzer, Morse oscillator, Poschl-Teller and Hulthen
potentials are used as reference potentials to obtain exact energy eigenvalues
and eigenfunctions for target potentials at different position-dependent mass
settings.Comment: 14 pages, no figures, to appear in J. Phys. A: Math. Ge
Relativistic Expansion of Electron-Positron-Photon Plasma Droplets and Photon Emission
The expansion dynamics of hot electron-positron-photon plasma droplets is
dealt with within relativistic hydrodynamics. Such droplets, envisaged to be
created in future experiments by irradiating thin foils with
counter-propagating ultra-intense laser beams, are sources of flashes of gamma
radiation. Warm electron-positron plasma droplets may be identified and
characterized by a broadened 511 keV line
Part of the D - dimensional Spiked harmonic oscillator spectra
The pseudoperturbative shifted - l expansion technique PSLET [5,20] is
generalized for states with arbitrary number of nodal zeros. Interdimensional
degeneracies, emerging from the isomorphism between angular momentum and
dimensionality of the central force Schrodinger equation, are used to construct
part of the D - dimensional spiked harmonic oscillator bound - states. PSLET
results are found to compare excellenly with those from direct numerical
integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge
Impact of Si nanocrystals in a-SiOx<Er> in C-Band emission for applications in resonators structures
Si nanocrystals (Si-NC) in a-SiOx were created by high temperature
annealing. Si-NC samples have large emission in a broadband region, 700nm to
1000nm. Annealing temperature, annealing time, substrate type, and erbium
concentration is studied to allow emission at 1550 nm forsamples with erbium.
Emission in the C-Band region is largely reduced by the presence of Si-NC. This
reduction may be due to less efficient energy transfer processes from the
nanocrystals than from the amorphous matrix to the Er3+ ions, perhaps due to
the formation of more centro-symmetric Er3+ sites at the nanocrystal surfaces
or to very different optimal erbium concentrations between amorphous and
crystallized samples.Comment: 3 pages, 4 figure
How rare is isolated rheumatic tricuspid valve disease?
The incidence of rheumatic fever (RF) has markedly decreased in Europe since the beginning of the 20th century due to improved living conditions, early antibiotic therapy in streptococcal pharyngitis, and changes in serotypes of circulating streptococci. Isolated outbreaks of RF are still found in various parts of the world and the disease has changed its presentation with milder joint symptoms and subclinical carditis that make the correct diagnosis more difficult. Patients can present many years later with severe valve disease and significant disability. This article presents a case of isolated rheumatic tricuspid valve disease that presented with signs and symptoms of right heart failure and severe valve damage. Isolated involvement of the tricuspid valve is rarely found in rheumatic fever and a thorough differential diagnosis is needed
Generalized inequalities on warped product submanifolds in nearly trans-Sasakian manifolds
In this paper, we study warped product submanifolds of nearly trans-Sasakian
manifolds. The non-existence of the warped product semi-slant submanifolds of
the type is shown, whereas some characterization and
new geometric obstructions are obtained for the warped products of the type
. We establish two general inequalities for the
squared norm of the second fundamental form. The first inequality generalizes
derived inequalities for some contact metric manifolds [16, 18, 19, 24], while
by a new technique, the second inequality is constructed to express the
relation between extrinsic invariant (second fundamental form) and intrinsic
invariant (scalar curvatures). The equality cases are also discussed.Comment: 16 page
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