Related papers: Could Cosmic Rays Affect Instabilities in the Tran…
The acceleration of charged particles at astrophysical collisionless shock waves is one of the best studied processes for the energization of particles to ultrarelativistic energies, required by multifrequency observations in a variety of…
Shocks in granular media, such as vertically oscillated beds, have been shown to develop instabilities. Similar jet formation has been observed in explosively dispersed granular media. Our previous work addressed this instability by…
Interpretations of synchrotron observations often assume a tight correlation between magnetic and cosmic ray energy densities. We examine this assumption using both test-particle simulations of cosmic rays and MHD simulations which include…
We use particle-in-magnetohydrodynamics-cells to model particle acceleration and magnetic field amplification in a high Mach, parallel shock in three dimensions and compare the result to 2-D models. This allows us to determine whether 2-D…
Energetic astrophysical phenomena, such as $\gamma$-ray bursts and supernova explosion-driven shocks in collisionless plasmas, involve various plasma kinetic instabilities, such as the Weibel instability. In this paper, we explore the…
Using the multi-fluid approach, we investigate streaming and thermal instabilities of the electron-ion plasma with homogeneous cold cosmic rays drifting perpendicular to the background magnetic field. Perturbations across the magnetic field…
We calculate the power spectrum of density fluctuations in the statistical non-equilibrium field theory for classical, microscopic degrees of freedom to first order in the interaction potential. We specialise our result to cosmology by…
We consider the propagation of galactic cosmic rays under assumption that the interstellar medium is a fractal one. An anomalous diffusion equation in terms of fractional derivatives is used to describe of cosmic ray propagation. The…
We model the Parker instability in vertically stratified isothermal gas using non-ideal MHD three-dimensional simulations. Rotation, especially differential, more strongly and diversely affects the nonlinear state than the linear stage…
We analyze the generation of kinetic instabilities and their effect on the energization of ions in non-relativistic, oblique collisionless shocks using a 3D-3V simulation by $\texttt{dHybridR}$, a hybrid particle-in-cell code. At…
Collisionless plasma shock theory, which applies for example to the afterglow of gamma ray bursts, still contains key issues that are poorly understood. In this paper we study charged particle dynamics in a highly relativistic collisionless…
Here we present a commentary on the role of small-scale (e.g., few tens of meters) wave-particle interactions in large-scale (e.g., few tens of kilometers) processes and their capacity to accelerate particles from thermal to suprathermal or…
In collision-poor plasmas from space, three distinct ion-ion instabilities can be driven by the proton beams streaming along the background magnetic field: left-hand resonant, non-resonant, and right-hand resonant instabilities. These…
Several important mechanisms that explain the coherent pulsar radio emission rely on streaming (or beam) instabilities of the relativistic pair plasma in a pulsar magnetosphere. However, it is still not clear whether a streaming instability…
High-energy astrophysical systems frequently contain collisionless relativistic plasmas that are heated by turbulent cascades and cooled by emission of radiation. Understanding the nature of this radiative turbulence is a frontier of…
The expansion of two circular rarefaction waves in vacuum or in a thin ambient plasma is examined with particle-in-cell simulations that resolve two spatial dimensions. In the simulation with no ambient plasma, the rarefaction waves…
The flux of ultrahigh energy cosmic rays reaching the Earth is affected by the interactions with the cosmic radiation backgrounds as well as with the magnetic fields that are present along their trajectories. We combine the SimProp cosmic…
Non-thermal (relativistic) particles are injected into the cosmos by structure formation shock waves, active galactic nuclei and stellar explosions. We present a suite of unigrid cosmological simulations (up to $2048^3$) using a two-fluid…
Theoretical concepts ofn cosmic ray particle acceleration at relativistic plasma flows -- shocks and shear layers -- are reviewed. We begin with a discussion of mildly relativistic shock waves. The role of oblique field configurations and…
A direct numerical simulation of a strong relativistic collisionless shock propagating into an unmagnetized medium has been performed in two spatial dimensions. It is found that: (i) collisionless shock exists, (ii) particle acceleration is…