Electromagnetic waves in an axion-active relativistic plasma non-minimally coupled to gravity (original) (raw)

Axion-induced oscillations of cooperative electric field in a cosmic magneto-active plasma

The European Physical Journal D, 2014

We consider one cosmological application of an axionic extension of the Maxwell-Vlasov theory, which describes axionically induced oscillatory regime in the state of global magnetic field evolving in the anisotropic expanding (early) universe. We show that the cooperative electric field in the relativistic plasma, being coupled to the pseudoscalar (axion) and global magnetic fields, plays the role of a regulator in this three-level system; in particular, the cooperative (Vlasov) electric field converts the regime of anomalous growth of the pseudoscalar field, caused by the axion-photon coupling at the inflationary epoch of the universe expansion, into an oscillatory regime with finite density of relic axions. We analyze solutions to the dispersion equations for the axionically induced cooperative oscillations of the electric field in the relativistic plasma.

Gravitational waves in magnetized relativistic plasmas

Physical Review D, 2004

We study the propagation of gravitational waves (g w) in a uniformly magnetized plasma at arbitrary angles to the magnetic field. No a priori assumptions are made about the temperature, and we consider both a plasma at rest and a plasma flowing out at ultra-relativistic velocities. In the 3+1 orthonormal tetrad description, we find th at all three fundamental low-frequency plasma wave modes are excited by the g w. Alfven waves are excited by a x polarized g w , whereas the slow and fast magneto-acoustic modes couple to the + polarization. The slow mode, however, doesn't interact coherently with the g w. The most relevant wave mode is the fast magneto-acoustic mode which in a strongly magnetized plasma has a vanishingly small phase lag with respect to the g w allowing for coherent interaction over large length scales. W hen the background magnetic field is almost, but not entirely, parallel to the GW's direction of propagation even the Alfven waves grow to first order in the GW amplitude. Finally, we calculate the growth of the magneto-acoustic waves and the damping of the GW.

Resonant interaction between gravitational waves, electromagnetic waves, and plasma flows

Physical Review D, 2003

In magnetized plasmas gravitational and electromagnetic waves may interact coherently and exchange energy between themselves and with plasma flows. We derive the wave interaction equations for these processes in the case of waves propagating perpendicular or parallel to the plasma background magnetic field. In the latter case, the electromagnetic waves are taken to be circularly polarized waves of arbitrary amplitude. We allow for a background drift flow of the plasma components which increases the number of possible evolution scenarios. The interaction equations are solved analytically and the characteristic time scales for conversion between gravitational and electromagnetic waves are found. In particular, it is shown that in the presence of a drift flow there are explosive instabilities resulting in the generation of gravitational and electromagnetic waves. Conversely, we show that energetic waves can interact to accelerate particles and thereby produce a drift flow. The relevance of these results for astrophysical and cosmological plasmas is discussed.

Transverse wave propagation in relativistic two-fluid plasmas in de Sitter space

General Relativity and Gravitation, 2009

We investigate transverse electromagnetic waves propagating in a plasma in the de Sitter space. Using the 3 + 1 formalism we derive the relativistic two-fluid equations to take account of the effects due to the horizon and describe the set of simultaneous linear equations for the perturbations. We use a local approximation to investigate the one-dimensional radial propagation of Alfvén and high frequency electromagnetic waves and solve the dispersion relation for these waves numerically.

Extended axion electrodynamics: Anomalous dynamo-optical response induced by gravitational pp-waves

Gravitation and Cosmology

We extend the Einstein-Maxwell-axion theory including into the Lagrangian cross-terms of the dynamo-optical type, which are quadratic in the Maxwell tensor, linear in the covariant derivative of the macroscopic velocity four-vector, and linear in the pseudoscalar (axion) field or its gradient four-vector. We classify the new terms with respect to irreducible elements of the covariant derivative of the macroscopic velocity four-vector of the electromagnetically active medium: the expansion scalar, acceleration four-vector, shear and vorticity tensors. Master equations of the extended axion electrodynamics are used for the description of the response of an axionically active electrodynamic system, induced by a pp-wave gravitational background. We show that this response has a critical character, i.e., the electric and magnetic fields, dynamo-optically coupled to the axions, grow anomalously under the influence of the external pp-wave gravitational field. * Electronic address: Alexander.Balakin@kpfu.ru † Electronic address: Timur.Alpin@kpfu.ru

Nonminimal Einstein–Maxwell–Vlasov-axion model

Classical and Quantum Gravity, 2014

We establish a new self-consistent system of equations accounting for a nonminimal coupling of the cooperative gravitational, electromagnetic and pseudoscalar (axion) fields in a multi-component relativistic plasma. The axionic extension of the nonminimal Einstein-Maxwell-Vlasov theory is based on two consistent procedures. First, we use the Lagrange formalism to obtain nonminimal equations for the gravitational, electromagnetic and pseudoscalar fields with the additional sources generated in plasma. Second, we use the Vlasov version of the relativistic kinetic theory of the plasma, guided by the cooperative macroscopic electromagnetic, gravitational and axionic fields, to describe adequately the response of the plasma on the variations of these fields. In order to show the self-consistency of this approach we check directly the compatibility conditions for the master equations for the cooperative fields. Using these compatibility conditions we reconstruct the ponderomotive force, which acts on the plasma particles, and discuss the necessary conditions for existence of the distribution function of the equilibrium type.

Transverse wave propagation in relativistic two-fluid plasmas around Reissner–Nordström–de Sitter black hole

General Relativity and Gravitation, 2010

The transverse electromagnetic waves propagating in a relativistic two-fluid plasma influenced by the gravitational field of the Reissner-Nordström-de Sitter black hole has been investigated exploiting 3+1 split of spacetime. Reformulating the two-fluid equations, the set of simultaneous linear equations for the perturbations have been derived. Using a local approximation, the one-dimensional radial propagation of Alfvén and high frequency electromagnetic waves are investigated. The dispersion relation for these waves is obtained and solved numerically for the wave number.

Nonlinear gravitational wave interactions with plasmas

Physical Review D, 2000

We consider the interactions of a strong gravitational wave with electromagnetic fields using the 1ϩ3 orthonormal tetrad formalism. A general system of equations is derived, describing the influence of a plane fronted parallel (pp) gravitational wave on a cold relativistic multicomponent plasma. We focus our attention on phenomena that are induced by terms that are higher order in the gravitational wave amplitude. In particular, it is shown that parametric excitations of plasma oscillations take place, due to higher order gravitational nonlinearities. The implications of the results are discussed.

Covariant constitutive relations and relativistic inhomogeneous plasmas

Journal of Mathematical Physics, 2011

The notion of a two-point susceptibility kernel used to describe linear electromagnetic responses of dispersive continuous media in non-relativistic phenomena is generalized to accommodate the constraints required of a causal formulation in spacetimes with background gravitational fields. In particular the concepts of spatial material inhomogeneity and temporal non-stationarity are formulated within a fully covariant spacetime framework. This framework is illustrated by re-casting the Maxwell-Vlasov equations for a collisionless plasma in a form that exposes a 2-point electromagnetic susceptibility kernel in spacetime. This permits the establishment of a perturbative scheme for non-stationary inhomogeneous plasma configurations. Explicit formulae for the perturbed kernel are derived in both the presence and absence of gravitation using the general solution to the relativistic equations of motion of the plasma constituents. In the absence of gravitation this permits an analysis of collisionless damping in terms of a system of integral equations that reduce to standard Landau damping of Langmuir modes when the perturbation refers to a homogeneous stationary plasma configuration. It is concluded that constitutive modelling in terms of a 2-point susceptibility kernel in a covariant spacetime framework offers a natural extension of standard non-relativistic descriptions of simple media and that its use for describing linear responses of more general dispersive media has wide applicability in relativistic plasma modelling.

Propagation of gravitational waves in a magnetized plasma

Physical Review D, 1983

The propagation of gravitational waves parallel and perpendicular to a magnetic field in a collisionless plasma is considered. In the parallel case weak cyclotron damping of the gravitational waves exists, while in the perpendicular case there is coupling between gravitational and electromagnetic waves due to the generation of currents by the gravitational wave.