Related papers: Velocity space compression from Fermi acceleration…
Astrophysical media are turbulent and therefore reconnection should be treated in the presence of pre-existing turbulence. We consider the model of fast magnetic reconnection in Lazarian & Vishniac (1999) which predicts that the rate of…
Shocks in astrophysical fluids can generate suprathermal particles by first order (or diffusive) Fermi acceleration. In the test particle regime there is a simple relation between the spectrum of the accelerated particles and the jump…
In this article, momentum transport generated by the combined effects of pitch-angle diffusion and Background Flow Velocity Inhomogeneities (BFVIs) is proposed to obtain a cosmic rays acceleration mechanism, starting from the well-known…
In solar flares and other astrophysical systems, a major challenge for solving particle acceleration problem associated with magnetic reconnection is the enormous scale separation between kinetic scales and observed reconnection scale.…
In this chapter, we review some features of particle acceleration in astrophysical jets. We begin by describing four observational results relating to the topic, with particular emphasis on jets in active galactic nuclei and parallels…
The problem of anomalous diffusion in momentum space is considered for plasma-like systems on the basis of a new collision integral, which is appropriate for consideration of the probability transition function (PTF) with long tails in…
Fast magnetic reconnection may occur in different astrophysical sources, producing flare-like emission and particle acceleration. Currently, this process is being studied as an efficient mechanism to accelerate particles via a first-order…
We formulate the first order Fermi acceleration in parallel shock waves in terms of the random walk theory. The formulation is applicable to any value of the shock speed and the particle speed, in particular to the acceleration in…
We analyse processes of particle acceleration in the Fermi Bubbles. The goal of our investigations is to obtain restrictions for acceleration mechanisms. Our analysis of the three processes: acceleration from background plasma,…
One of the main features of astrophysical shocks is their ability to accelerate particles to extremely high energies. The leading acceleration mechanism, the diffusive shock acceleration is reviewed. It is demonstrated that its efficiency…
Recently, the {\it{Fermi}} space telescope has discovered two large $\gamma$-ray emission regions, the so-called "Fermi bubbles", that extend up to $\sim 50^\circ$ above and below the Galactic center. The $\gamma$-ray emission from the…
We explain an accelerated expansion of the present universe, suggested from observations of supernovae of type Ia at high redshift, by introducing an anti-frictional force that is self-consistently exerted on the particles of the cosmic…
In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury,energetic electrons are often found near current sheets (CSs), which hints at electron acceleration by magnetic reconnection. Unfortunately, electron…
Accretion flows onto supergalactic-scale structures are accompanied with large spatial scale shock waves. These shocks were postulated as possible sources of ultra-high energy cosmic rays. The highest particle energies were expected for…
Ultrafast optical excitation of metals induces a non-equilibrium energy distribution in the electronic system, with a characteristic step-structure determined by Pauli blocking. On a femtosecond timescale, electron-electron scattering…
We explore the physics of electron acceleration in a plasma medium in an effective field theory framework. Employing a multiple Compton scattering mechanism, it is found that the acceleration can be sustained in such a medium so as to…
A stochastic model is proposed for the acceleration of non-relativistic particles yielding to energy spectra with a shape of a Weibull\textquoteright s function. Such particle distribution is found as the stationary solution of a…
We simulate the acceleration processes of collisionless particles in a shock structure with magnetohydrodynamical (MHD) fluctuations. The electromagnetic field is represented as a sum of MHD shock solution ($\Mag_0, \Ele_0$) and torsional…
The new numerical version of the Wigner approach to quantum mechanics for treatment thermodynamic properties of strongly coupled systems of particles has been developed for extreme conditions, when analytical approximations obtained in…
Fermi bubbles are giant gamma-ray structures extended north and south of the Galactic center with characteristic sizes of order of 10 kpc recently discovered by Fermi Large Area Telescope. Good correlation between radio and gamma-ray…