Related papers: Nonlinear Electromagnetic Fields As a Source of Un…
We examine the impact of several factors on electron acceleration by a laser pulse and the resulting electron energy gain. Specifically, we consider the role played by: 1) static longitudinal electric field; 2) static transverse electric…
Particle acceleration consequences from fluctuating electric fields superposed on an X-type magnetic field in collisionless solar plasma are studied. Such a system is chosen to mimic generic features of dynamic reconnection, or the…
The question as to whether neutron acceleration can occur in uniform electromagnetic fields is examined. Although such an effect has been predicted using the canonical equations of motion some doubt has been raised recently as to whether it…
We present a five dimensional unified theory of gravity and electromagnetism which leads to modified Maxwell equations, suggesting a new origin for galactic magnetic fields. It is shown that a region with nonzero scalar curvature would…
Electrophoresis is the motion of particles relative to a surrounding fluid driven by a uniform electric field. In conventional electrophoresis, the electrophoretic velocity grows linearly with the applied field. Nonlinear effects with a…
We address the scaling behavior of the covariance of the magnetic field in the three-dimensional kinematic dynamo problem when the boundary conditions and/or the external forcing are not isotropic. The velocity field is gaussian and…
The evolution of the non-thermal emission emitted by pulsar wind nebulae is generally calculated using spatially-independent particle transport models. Although useful, these models implicitly assume that the source of non-thermal particles…
In this paper we present a model for accelerated expansion of the universe, both during inflation and the present stage of the expansion, from four dimensional $\mathcal{N}=1$ supergravity. We evaluate the tensor-to-scalar ratio ($r\approx…
Inflationary spatially homogeneous cosmological models within an Einstein-Aether gravitational framework are investigated. The matter source is assumed to be a scalar field which is coupled to the aether field expansion and shear scalars…
In this paper, we present a cosmological model within the framework of symmetric teleparallel gravity, focusing on $f(Q)$ gravity, where $Q$ represents the non-metricity scalar. Utilizing cosmological datasets, we derive an accelerating…
The motion of electrons and positrons in the vacuum magnetosphere of a neutron star with a surface magnetic field of B~10^12 G is considered. Particles created in the magnetosphere or falling into it from outside are virtually…
In energetic nonthermal sources such as gamma-ray bursts, AGN or galactic jet sources, etc., one expects both relativistic and transrelativistic shocks acompanied by violent motions of moderately relativistic plasma. We present general…
Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest…
Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are…
In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…
In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…
Time-dependent nonlinear media, such as rapidly generated plasmas produced via laser ionization of gases, can increase the energy of individual laser photons and generate tunable high-order harmonic pulses. This phenomenon, known as photon…
Recently WMAP and BOOMERanG experiments have set stringent constraints on the polarization angle of photons propagating in an expanding universe: $\Delta \alpha = (-2.4 \pm 1.9)^\circ$. The polarization of the Cosmic Microwave Background…
No. It is simply not plausible that cosmic acceleration could arise within the context of general relativity from a back-reaction effect of inhomogeneities in our universe, without the presence of a cosmological constant or ``dark energy.''…
A novel nonlinear electrodynamics (NLE) model with two dimensionful parameters is introduced and investigated. Our model obeys the Maxwellian limit and exhibits behaviour similar to the Born-Infeld Lagrangian in the weak field limit. It is…