Dispersion Properties of Co-Existing Low Frequency Modes in Quantum Plasmas (original) (raw)
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In electron-positron plasmas some of the plasma modes are decoupled due to the equal charge to mass ratio of both species. The dispersion properties of the propagation of linear waves in degenerate electron-positron magnetoplasma are investigated. By using the quantum hydrodynamic equations with magnetic fields of the Wigner-Maxwell system, we have obtained a set of new dispersion relations in which ions' motions are not considered. The general dielectric tensor is derived using the electron and positron densities and its momentum response to the quantum effects due to Bohm potential and the statistical effect of Femi temperature. It has been demonstrated the importance of magnetic field and its role with the quantum effects in these plasmas which support the propagation of electromagnetic linear waves. Besides, the dispersion relations in case of parallel and perpendicular modes are investigated for different positron-electron density ratios.
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This work is submitted as a dissertation in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN PHYSICS in the D e p a r t m e n t o f P h y s i c s COMSATS Institute of Information Technology I s l a m a b a d P a k i s t a n A u g u s t 2 0 0 9 This work is supported by Higher Education Commission (HEC) Pakistan under Indigenous PhD Fellowship Program (5000): No. 1751(P149)/HEC/Sch/2004
arXiv: Plasma Physics, 2017
The low frequency, long wavelength electromagnetic waves, viz, shear Alfven wave in quantum electron-positron-ion magneto plasmas, have been examined using quantum magneto hydrodynamic model. In this model, we have considered electrons and positrons are to be magnetized as well as degenerate whereas ions are magnetized but classical. We have also included the effects of exchange correlation terms which appear entirely the dynamic equations of electrons and positrons. The whole treatment is done using multi-fluid model. Our object is to study the shear Alfv\'en waves propagating in above said system of plasma. For that we have derived the modified dispersion relation of the shear Alfv\'en waves. Results are relevant to the terrestrial laboratory astrophysics.
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Physical Review D, 2000
The propagation of excitation modes in a relativistic ultradegenerate plasma is modified by their interactions with the medium. These modifications can be computed by evaluating their on-shell self-energy, which gives (gaugeindependent) dispersion relations. For modes with momentum close to the Fermi momentum, the one-loop fermion self-energy is dominated by a diagram with a soft photon in the loop. We find the one-loop dispersion relations for quasiparticles and antiquasiparticles, which behave differently as a consequence of their very different phase-space restrictions when they scatter with the electrons of the Fermi sea. In a relativistic system, the unscreened magnetic interactions spoil the normal Fermi liquid behavior of the plasma. For small values of the Fermi velocity, we recover the non-relativistic dispersion relations of condensed matter systems.