Related papers: Particle acceleration in astrophysical shear flows
Inhomogeneities in the velocity field of a moving fluid are dampened by the inherent viscous behaviour of the system. Both bulk and shear effects, related to the divergence and the curl of the velocity field, are relevant. On molecular time…
Counterpropagating Alfv\'en waves are ubiquitously observed in many astrophysical environments, such as a star surface and a planetary foreshock. We discuss an efficient particle acceleration mechanism in two counterpropagating circularly…
We discuss a role of the boundary shear layer of large scale jets for their observed multiwavelength emission. We consider a simple mechanism of a turbulent particle acceleration acting within such regions as an alternative mechanism with…
Addition of particles to a viscoelastic suspension dramatically alters the properties of the mixture, particularly when it is sheared or otherwise processed. Shear-induced stretching of the polymers results in elastic stress that causes a…
A new particle acceleration process in a developing Alfv\'{e}n turbulence in the course of successive parametric instabilities of a relativistic pair plasma is investigated by utilyzing one-dimensional electromagnetic full particle code.…
Active Galactic Nuclei (AGN) and their relativistic jets are believed to be potential sites of ultra-high-energy (UHE) cosmic ray acceleration. This paper reviews basic observational findings as well as requirements on source energetics,…
The dissipation of energy from local velocity perturbations in the cosmological fluid affects the time evolution of spatially averaged fluid dynamic fields and the cosmological solution of Einstein's field equations. We show how this…
This proceedings paper reports on the theoretical modelling of particle acceleration in magnetised turbulent plasmas. It briefly reviews some recent findings obtained from fully kinetic numerical simulations of large-amplitude, semi to…
We investigate the effect of shear in the flow of charged particle equilibria that are unstable to the Coherent Synchrotron Radiation (CSR) instability. Shear may act to quench this instability because it acts to limit the size of the…
We consider the transverse structure and stability properties of relativistic jets formed in the course of the collapse of a massive progenitor. Our numerical simulations show the presence of a strong shear in the bulk velocity of such…
The Brownian motion of a particle in a harmonic potential, which is simultaneously exposed either to a linear shear flow or to a plane Poiseuille flow is investigated. In the shear plane of both flows the probability distribution of the…
We present the first radio emission simulations from high resolution three dimensional relativistic hydrodynamic jets, which allow for a study of the observational implications of the interaction between the jet and external medium. This…
Conventionally, friction is understood as an efficient dissipation mechanism depleting a physical system of energy as an unavoidable feature of any realistic device involving moving parts, e.g., in mechanical brakes. In this work, we…
We consider radiation of relativistic electrons accelerated within the jet extended boundary layer. Due to velocity shear across the boundary the observed jet/counterjet brightness ratio is diminished as compared to the one derived for the…
In the broad line region of AGN, acceleration occurs naturally when a cloud condenses out of the hot confining medium due to the increase in line opacity as the cloud cools. However, acceleration by radiation pressure is not very efficient…
We study the long time behaviour of the speed of a particle moving in $\mathbb{R}^d$ under the influence of a random time-dependent potential representing the particle's environment. The particle undergoes successive scattering events that…
We have investigated the influence of velocity shear and a radial density profile on the spatial development of the current driven kink instability along helically magnetized relativistic jets via three-dimensional relativistic…
Relativistic jets, or highly collimated and fast-moving outflows, are endemic to many astrophysical phenomena. The jets produced by gamma-ray bursts and tidal disruption events are accompanied by the accretion of material onto a black hole…
Particle acceleration in the inner ~ 200 pc of the Galaxy is discussed, where diffuse TeV gamma-rays have been detected by the High Energy Stereoscopic System (HESS) observation. The diffuse gamma-ray emission has a strong correlation with…
Cosmic rays are charged particles that are accelerated to relativistic speeds by astrophysical shocks. Numerical models have been successful in confirming the acceleration process for (quasi-)parallel shocks, which have the magnetic field…