scholarly journals Relaxation schemes for normal modes of magnetic vortices: Application to the scattering matrix

2001 ◽  
Vol 63 (9) ◽  
Author(s):  
G. M. Wysin
Keyword(s):  
Normal Modes ◽  
Scattering Matrix ◽  
Magnetic Vortices ◽  
Relaxation Schemes

A study of the coupled gravitational and electromagnetic perturbations to the Reissner-Nordström black hole: the scattering matrix, energy conversion, and quasi-normal modes

1980 ◽  
Vol 296 (1422) ◽  
pp. 497-526 ◽  
Keyword(s):  
Black Hole ◽  
Electromagnetic Waves ◽  
Wave Equations ◽  
Normal Modes ◽  
Scattering Matrix ◽  
Gravitational Energy ◽  
Reflection And Transmission ◽  
Potential Barriers ◽  
Factor C ◽  
Incident Waves

The reflection and absorption, by the charged spherically symmetric Reissner-Nordström black hole, of an arbitrary superposition of gravitational and electromagnetic waves, with time dependence e iot and analyzed into spherical harmonics of various orders l , are expressed in terms of the complex reflection and transmission amplitudes (for incident waves) by two one-dimensional potential barriers. These amplitudes, expressed in terms of eight quantities (and composing the scattering matrix), are tabulated for various values of o,l (= 2, 3, and 6) and charge of the black hole. By virtue of the coupling of electromagnetic and gravitational perturbations by the charge of the black hole, the energy in an incident wave, which is purely gravitational, is, in part, reflected as electromagnetic waves; and conversely. This transformation of incident gravitational energy into electromagnetic energy (and vice versa) is expressed in terms of a conversion factor C and plotted in a series of graphs as a function of o for various values of l and the charge on the black hole Q * . Finally, the complex frequencies belonging to the quasi-normal modes (i.e., solutions of the underlying wave equations which correspond to purely outgoing waves at infinity and purely ingoing waves at the horizon) are tabulated. It is found that the imaginary part of these frequencies (which determine the damping of arbitrary initial perturbations of the black hole) is very nearly the same for all modes (with different l ’s) and Q * .

Erratum

1981 ◽  
Vol 301 (1462) ◽  
pp. 705-709 ◽  
Keyword(s):  
Black Hole ◽  
Energy Conversion ◽  
Normal Modes ◽  
Scattering Matrix ◽  
Electromagnetic Perturbations

A study of the coupled gravitational and electromagnetic perturbations to the Reissner-Nordström black hole: the scattering matrix, energy conversion, and quasi-normal modes

scholarly journals Движение взаимодействующих магнитных вихрей в параллельных нанолентах

2019 ◽  
Vol 61 (3) ◽  
pp. 493
Author(s):  
В.А. Орлов ◽  
А.А. Иванов ◽  
И.Н. Орлова
Keyword(s):  
Magnetic Field ◽  
Periodic Motion ◽  
Topological Charge ◽  
Domain Walls ◽  
Normal Modes ◽  
Elastic Coupling ◽  
Magnetic Vortices ◽  
Static Component ◽  
Resonant Behavior ◽  
Ac Fields

AbstractThe periodic motion of the interacting vortex domain walls in a pair of nanostripes has been theoretically investigated. As a model, two parallel nanostripes with magnetization inhomogeneities in the form of magnetic vortices have been examined. The magnetic subsystems of the stripes are magnetostatically coupled. The quasi-elastic coupling between vortices ensures the existence of normal modes of the periodic magnetization motion. The frequencies of these modes have been calculated. It is shown that not any combination of the vortex topological charge leads to the resonant behavior of magnetization in ac fields. The effect of the static component of a magnetic field on the frequency of the periodic motion of vortex domain walls is discussed.

scholarly journals Cross Sections and Rate Coefficients for Vibrational Excitation of H2O by Electron Impact

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 62
Author(s):  
Mehdi Ayouz ◽  
Alexandre Faure ◽  
Jonathan Tennyson ◽  
Maria Tudorovskaya ◽  
Viatcheslav Kokoouline
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Vibrational Excitation ◽  
Normal Modes ◽  
Scattering Matrix ◽  
Rate Coefficients ◽  
Vibrational States ◽  
R Matrix ◽  
Frame Transformation ◽  
The Uk

Cross-sections and thermally averaged rate coefficients for vibration (de-)excitation of a water molecule by electron impact are computed; one and two quanta excitations are considered for all three normal modes. The calculations use a theoretical approach that combines the normal mode approximation for vibrational states of water, a vibrational frame transformation employed to evaluate the scattering matrix for vibrational transitions and the UK molecular R-matrix code. The interval of applicability of the rate coefficients is from 10 to 10,000 K. A comprehensive set of calculations is performed to assess uncertainty of the obtained data. The results should help in modelling non-LTE spectra of water in various astrophysical environments.

“Preparation of Single Crystalline Gold Films for ED Studies”

1972 ◽  
Vol 30 ◽  
pp. 634-635
Author(s):  
Joseph D. C. Peng
Keyword(s):  
Crystal Morphology ◽  
Diffraction Theory ◽  
Scattering Matrix ◽  
Vacuum Evaporation ◽  
Gold Films ◽  
Matrix Formulation ◽  
Silver Films ◽  
Single Crystalline ◽  
Grating Pattern ◽  
Stacking Disorder

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.

Current driven organization of magnetic vortices

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-5-Pr10-9
Author(s):  
E. Y. Andrei ◽  
Z. L. Xiao ◽  
W. Henderson ◽  
M. J. Higgins ◽  
P. Shuk ◽  
...  
Keyword(s):  
Magnetic Vortices

Reduction of the scattering matrix array

2015 ◽  
Vol 185 (9) ◽  
pp. 941-945 ◽  
Author(s):  
Ivan A. Sadovskyy
Keyword(s):  
Scattering Matrix ◽  
Matrix Array

Scattering Matrix in the DKP Theory. Barrier Potential Case

2014 ◽  
Vol 59 (6) ◽  
pp. 565-568 ◽  
Author(s):  
Boutabia-Chéraitia B. Boutabia-Chéraitia B. ◽  
◽  
Boudjedaa T. Boudjedaa T. ◽  
Keyword(s):  
Scattering Matrix ◽  
Barrier Potential ◽  
Potential Case

Filtering methods for finite-time normal modes and atmospheric error growth

2000 ◽  
Vol 42 ◽  
pp. 1482
Author(s):  
Mozheng Wei ◽  
Jorgen S. Frederiksen ◽  
Steve Kepert
Keyword(s):  
Finite Time ◽  
Normal Modes ◽  
Error Growth
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