Strings and dyonic plasmas

Nonlinear Processes in Geophysics, 2008

Dispersive properties of linear and nonlinear MHD waves, including shear, kinetic, electron inertial Alfvén, and slow and fast magnetosonic waves are analyzed using both analytical expansions and a novel technique of dispersion diagrams. The analysis is extended to explicitly include space charge effects in non-neutral plasmas. Nonlinear soliton solutions, here called alfvenons, are found to represent either convergent or divergent electric field structures with electric potentials and spatial dimensions similar to those observed by satellites in auroral regions. Similar solitary structures are postulated to be created in the solar corona, where fast alfvenons can provide acceleration of electrons to hundreds of keV during flares. Slow alfvenons driven by chromospheric convection produce positive potentials that can account for the acceleration of solar wind ions to 300-800 km/s. New results are discussed in the context of observations and other theoretical models for nonlinear Alfvén waves in space plasmas.

High field terahertz emission from relativistic laser-driven plasma wakefields Phys. Plasmas 22, 103105 (2015); 10.1063/1.4933130 Nonlinear Raman forward scattering driven by a short laser pulse in a collisional transversely magnetized plasma with nonextensive distribution Phys. Plasmas 22, 092128 (2015); 10.1063/1.4931747 Effects of high energy photon emissions in laser generated ultra-relativistic plasmas: Real-time synchrotron simulations Phys. Plasmas 22, 033117 (2015); 10.1063/1.4916491 Energy partition, γ-ray emission, and radiation reaction in the near-quantum electrodynamical regime of laserplasma interaction Phys. Plasmas 21, 023109 (2014); 10.1063/1.4866014

Advances in High Energy Physics

The dual magnetohydrodynamics of dyonic plasma describes the study of electrodynamics equations along with the transport equations in the presence of electrons and magnetic monopoles. In this paper, we formulate the quaternionic dual fields equations, namely, the hydroelectric and hydromagnetic fields equations which are an analogous to the generalized Lamb vector field and vorticity field equations of dyonic cold plasma fluid. Further, we derive the quaternionic Dirac-Maxwell equations for dual magnetohydrodynamics of dyonic cold plasma. We also obtain the quaternionic dual continuity equations that describe the transport of dyonic fluid. Finally, we establish an analogy of Alfven wave equation which may generate from the flow of magnetic monopoles in the dyonic field of cold plasma. The present quaternionic formulation for dyonic cold plasma is well invariant under the duality, Lorentz, and CPT transformations.

1996

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IEEE Transactions on Plasma Science, 2015

The linear and nonlinear properties of ion acoustic excitations propagating in warm dense electron-positron-ion plasma are investigated. Electrons and positrons are assumed relativistic and degenerate, following the Fermi-Dirac statistics, whereas the warm ions are described by a set of classical fluid equations. A linear dispersion relation is derived in the linear approximation. Adopting a reductive perturbation method, the Korteweg-de Vries equation is derived, which admits a localized wave solution in the form of a small-amplitude weakly super-acoustic pulse-shaped soliton. The analysis is extended to account for arbitrary amplitude solitary waves, by deriving a pseudoenergy-balance like equation, involving a Sagdeev-type pseudopotential. It is shown that the two approaches agree exactly in the small-amplitude weakly super-acoustic limit. The range of allowed values of the pulse soliton speed (Mach number), wherein solitary waves may exist, is determined. The effects of the key plasma configuration parameters, namely, the electron relativistic degeneracy parameter, the ion (thermal)-to-the electron (Fermi) temperature ratio, and the positron-to-electron density ratio, on the soliton characteristics and existence domain, are studied in detail. Our results aim at elucidating the characteristics of ion acoustic excitations in relativistic degenerate plasmas, e.g., in dense astrophysical objects, where degenerate electrons and positrons may occur. Index Terms-Plasma oscillations, plasma waves. I. INTRODUCTION R ECENTLY there has been a great deal of interest in elucidating the dynamics of collective processes in degenerate dense plasmas, commonly found in dense astrophysical objects (e.g., white and brown dwarfs, neutron stars, and magnetars), in the core of giant planets (e.g., Jovian planets), which can Manuscript

Physics of Plasmas, 2015

Linear properties of high and low frequency waves are studied in an electron-positron-ion (e-p-i) dense plasma with spin and relativity effects. In a low frequency regime, the magnetohydrodynamic (MHD) waves, namely, the magnetoacoustic and Alfven waves are presented in a magnetized plasma, in which the inertial ions are taken as spinless and non-degenerate, whereas the electrons and positrons are treated quantum mechanically due to their smaller mass. Quantum corrections associated with the spin magnetization and density correlations for electrons and positrons are reconsidered and a generalized dispersion relation for the low frequency MHD waves is derived to account for relativistic degeneracy effects. On the basis of angles of propagation, the dispersion relations of different modes are discussed analytically in a degenerate relativistic plasma. Numerical results reveal that electron and positron relativistic degeneracy effects significantly modify the dispersive properties of MHD waves. Our present analysis should be useful for understanding the collective interactions in dense astrophysical compact objects, like, the white dwarfs and in atmosphere of neutron stars. V

Astronomy and Astrophysics, 2006

Context. Solar plasmas are structured and stratified both vertically and horizontally. The presence of density gradients and magnetic fields results in an additional wave which can be electrostatic (the drift wave) and electromagnetic (the drift-Alfvén wave). Aims. The stability is discussed of the drift-Alfvén wave which is driven by the equilibrium density gradient, in both unbounded and bounded, collisional solar plasmas, including the effects of both hot ions and a finite ion Larmor radius. The density gradient in combination with the electron collisions with heavier plasma species is the essential source of the instability of the electrostatic drift mode which is coupled to the dispersive Alfvén mode. Methods. An analytical linear normal mode analysis is used for the description of the waves in spatially unlimited plasma. In the application to the magnetic structures the complex eigen-modes and the corresponding complex discrete eigen-frequencies in cylindric, radially inhomogeneous, collisional and bounded plasma are derived and discussed. Results. A detailed derivation of the hot ion (the finite ion Larmor radius) contribution is performed within the two fluid model. In the analysis of modes in an unbounded plasma the exchange of identity between the electrostatic and electromagnetic modes is demonstrated. Due to this, the frequency of the electromagnetic part of the mode becomes very different compared to the case without the density gradient. In the case of a bounded plasma the dispersion properties of modes involve a discrete poloidal mode number, and eigen-functions in terms of Bessel functions with discrete zeros at the boundary. The results are applied to coronal and chromospheric plasmas.

Astrophysics and Space Science, 1996

Contrary to popular and scientific opinion of just a few decades ago, space is not an ‘empty’ void. It is actually filled with high energy particles, magnetic fields, and highly conducting plasma. The ability of plasmas to produce electric fields, either by instabilities brought about by plasma motion or the movement of magnetic fields, has popularized the term ‘Electric Space’ in recognition of the electric fields systematically discovered and measured in the solar system. Today it is recognized that 99.999% of all observable matter in the universe is in the plasma state and the importance of electromagnetic forces on cosmic plasma cannot be overstated; even in neutral hydrogen regions (∼10−4 parts ionized), the electromagnetic force to gravitational force ratio is 107. An early prediction about the morphology of the universe is that it be filamentary (Alfvén, 1950). Plasmas in electric space are energetic (because of electric fields) and they are generally inhomogeneous with constituent parts in motion. Plasmas in relative motion are coupled by the currents they drive in each other and nonequilibrium plasma often consists of current-conducting filaments. This paper explores the dynamical and radiative consequences of the evolution of galactic-dimensioned filaments in electric space.

International Journal of Modern Physics A

By applying the Hamilton’s quaternion algebra, we propose the generalized electromagnetic-fluid dynamics of dyons governed by the combination of the Dirac–Maxwell, Bernoulli and Navier–Stokes equations. The generalized quaternionic hydro-electromagnetic field of dyonic cold plasma consists of electrons and magnetic monopoles in which there exist dual-mass and dual-charge species in the presence of dyons. We construct the conservation of energy and conservation of momentum equations by equating the quaternionic scalar and vector parts for generalized hydro-electromagnetic field of dyonic cold plasma. We propose the quaternionic form of conservation of energy is related to the Bernoulli-like equation while the conservation of momentum is related to Navier–Stokes-like equation for dynamics of dyonic plasma fluid. Further, the continuity equation, i.e. the conservation of electric and magnetic charges with the dynamics of hydro-electric and hydro-magnetic flow of conducting cold plasma ...