scholarly journals Magnetic field spectrum in a plasma in thermal equilibrium in the epoch of primordial nucleosynthesis

1997 ◽  
Vol 56 (6) ◽  
pp. 3296-3306 ◽  
Author(s):  
Merav Opher ◽  
Reuven Opher
Keyword(s):  
Magnetic Field ◽  
Thermal Equilibrium ◽  
Primordial Nucleosynthesis ◽  
Field Spectrum

Peculiarity Parameters

1976 ◽  
Vol 32 ◽  
pp. 233-254
Author(s):  
H. M. Maitzen
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Rotator Model ◽  
Peculiar Behaviour ◽  
Field Spectrum ◽  
Oblique Rotator ◽  
Ap Stars ◽  
The Way

Ap stars are peculiar in many aspects. During this century astronomers have been trying to collect data about these and have found a confusing variety of peculiar behaviour even from star to star that Struve stated in 1942 that at least we know that these phenomena are not supernatural. A real push to start deeper theoretical work on Ap stars was given by an additional observational evidence, namely the discovery of magnetic fields on these stars by Babcock (1947). This originated the concept that magnetic fields are the cause for spectroscopic and photometric peculiarities. Great leaps for the astronomical mankind were the Oblique Rotator model by Stibbs (1950) and Deutsch (1954), which by the way provided mathematical tools for the later handling pulsar geometries, anti the discovery of phase coincidence of the extrema of magnetic field, spectrum and photometric variations (e.g. Jarzebowski, 1960).

scholarly journals Nonlocal correlation in Heisenberg spin models

2017 ◽  
Vol 31 (23) ◽  
pp. 1750166 ◽  
Author(s):  
R. Muthuganesan ◽  
R. Sankaranarayanan
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Thermal Equilibrium ◽  
Quantum Discord ◽  
Spin Models ◽  
Heisenberg Spin ◽  
Geometric Quantum Discord ◽  
Nonlocal Correlation

In this paper, we investigate nonlocal correlation (beyond entanglement) captured by measurement induced nonlocality and geometric quantum discord for a pair of interacting spin-1/2 particles at thermal equilibrium. It is shown that both the measures are identical in measuring the correlation. We show that nonlocal correlation between the spins exist even without entanglement and the correlation vanishes only for maximal mixture of product bases. We also observe that while interaction between the spins is responsible for enhancement of correlation, this non-classicality decreases with the intervention of external magnetic field.

Theoretical cross-spectrum of the microfield measured by two small dipoles in a warm isotropic plasma

1977 ◽  
Vol 17 (2) ◽  
pp. 201-231 ◽  
Author(s):  
R. Pottelette ◽  
C. Chauliaguet ◽  
L. R. O. Storey
Keyword(s):  
Magnetic Field ◽  
Thermal Equilibrium ◽  
Plasma Frequency ◽  
Debye Length ◽  
Resonance Peak ◽  
Isotropic Plasma ◽  
Main Resonance ◽  
Mutual Impedance ◽  
Cross Spectrum ◽  
Electron Density And Temperature

We suggest that the electron density and temperature of a plasma could be determined by immersing two small dipole antennae in it, and by measuring, as a function of frequency, the cross-spectrum of the random signals that they receive. When the plasma is in thermal equilibrium, this spectrum is related simply, by Nyquist's theorem, to the real part of the mutual impedance of the two antennae. We have studied the case where, in addition, the plasma is collisionless and no magnetic field is present. The spectrum has a main resonance peak slightly above the plasma frequency, while for still higher frequencies it exhibits oscillations, the amplitudes of which decrease as one moves away from the plasma frequency. The main resonance peak becomes sharper, but smaller, as the distance between the antennae becomes large compared with the Debye length.

Magnetic Fields in Slowly Rotating Stars

1968 ◽  
Vol 1 (3) ◽  
pp. 89-89
Author(s):  
G.F. Davies
Keyword(s):  
Magnetic Field ◽  
Thermal Equilibrium ◽  
Meridional Circulation ◽  
Rotating Stars ◽  
Axially Symmetric ◽  
Equilibrium Solutions ◽  
Azimuthal Component ◽  
Special Cases ◽  
Field Lines ◽  
Rotating Star

Those solutions which have so far been obtained to the problem of a star with both rotation and a magnetic field have been for certain special cases, mostly time-independent. It is known that, except for stars with special rotation laws, a rotating star in hydrostatic equilibrium cannot maintain thermal equilibrium without generating slow meridional circulation of matter. It is also known that an axially symmetric field with no azimuthal component tends very strongly to keep the star in a state of isorotation, with the angular velocity constant along field lines. A magnetic field also tends to upset thermal equilibrium and produce meridional circulation. In the absence of rotation, an equilibrium poloidal field has recently been found for which there is no circulation. The present paper reports analogous equilibrium solutions for a star which is in uniform rotation.

Experimental determination of the magnetic field spectrum in the Helically Symmetric Experiment using passing particle orbits

2001 ◽  
Vol 8 (12) ◽  
pp. 5165-5170 ◽  
Author(s):  
J. N. Talmadge ◽  
V. Sakaguchi ◽  
F. S. B. Anderson ◽  
D. T. Anderson ◽  
A. F. Almagri
Keyword(s):  
Magnetic Field ◽  
Experimental Determination ◽  
Field Spectrum ◽  
Particle Orbits ◽  
The Magnetic Field

The action of Vlasov waves on the velocity distribution in a plasma

1961 ◽  
Vol 10 (3) ◽  
pp. 473-479 ◽  
Author(s):  
J. W. Dungey
Keyword(s):  
Magnetic Field ◽  
Phase Space ◽  
Velocity Distribution ◽  
Thermal Equilibrium ◽  
Limited Range ◽  
Dimensional Model ◽  
One Dimensional ◽  
A Current

A one-dimensional model with no magnetic field is considered. It is supposed that the plasma starts in thermal equilibrium and then a current is forced to grow. Instability leads to the growth of waves, which are shown to stir the distribution in phase space, but only over a limited range of velocity. It is concluded that in order to restore stability the energy in the wave must become comparable to the energy of drift.

FERMIONIC FOUR-LEVEL SYSTEM IN THE PRESENCE OF A TIME-DEPENDENT MAGNETIC FIELD

1996 ◽  
Vol 10 (14) ◽  
pp. 643-651 ◽  
Author(s):  
M.T. THOMAZ
Keyword(s):  
Magnetic Field ◽  
Time Evolution ◽  
Thermal Equilibrium ◽  
Initial Conditions ◽  
Time Dependent ◽  
Initial Vector ◽  
Vector State ◽  
Level System ◽  
Exact Time

The exact fermionic four-level system is studied in the presence of time-dependent magnetic field. The system is considered under two initial conditions: general initial vector state, and, at thermal equilibrium. The exact time evolution of one-particle operators is derived.

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