Related papers: Fermi Acceleration at relativistic Shocks
We study stochastic acceleration models for the Fermi bubbles. Turbulence is excited just behind the shock front via Kelvin--Helmholtz, Rayleigh--Taylor, or Richtmyer--Meshkov instabilities, and plasma particles are continuously accelerated…
We consider the acceleration of energetic particles by Fermi processes (i.e., diffusive shock acceleration, second order Fermi acceleration, and gradual shear acceleration) in relativistic astrophysical jets, with particular attention given…
What are the mechanisms of particle acceleration and radiation, as well as magnetic field build up and decay in relativistic shocks are open questions with important implications to various phenomena in high energy astrophysics. While the…
The subject of this paper is stochastic acceleration by plasma turbulence, a process akin to the original model proposed by Fermi. We review the relative merits of different acceleration models, in particular the so called first order Fermi…
We study relativistic unmagnetized collisionless shocks using unprecedentedly large particle-in-cell simulations of two-dimensional pair plasma. High energy particles accelerated by the shock are found to drive magnetic field evolution on a…
Landau Fermi liquid theory is a fixed point theory of metals that includes the forward scattering amplitudes as exact marginal couplings. However, the fixed point theory that only includes the strict forward scatterings is non-local in real…
This paper explores the effects of strong magnetic fields on the Compton scattering of relativistic electrons. Recent studies of upscattering and energy loss by relativistic electrons that have used the non-relativistic, magnetic Thomson…
Observational data require a rich variety of mechanisms to accelerate fast particles in astrophysical environments operating under different conditions. The mechanisms discussed in the literature include varying magnetic fields in compact…
Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma ray bursts. These sources…
In the presence of strong density stratification, turbulence can lead to a large-scale instability of a horizontal magnetic field if its strength is in a suitable range (within a few percent of the turbulent equipartition value). This…
Using a three dimensional relativistic particle-in-cell code we have performed numerical experiments of plasma shells colliding at relativistic velocities. Such scenarios are found in many astrophysical objects e.g. the relativistic outflow…
We reexamine stochastic Fermi acceleration (STFA) in the low energy (Newtonian) regime in the context of solar flares. The particle energization rate depends a dispersive term and a coherent gain term. The energy dependence of pitch angle…
Fermi-type shear particle acceleration is a promising mechanism for sustaining ultra-relativistic particles along the kilo-parsec scale jets in Active Galactic Nuclei (AGNs). We explore the possibility of synchrotron-limited electron…
Fermi acceleration is believed as a crucial process for the acceleration of energetic electrons within flux ropes (FRs) during magnetic reconnection. However, in finite-length FRs with a large core field, the finite contracting and the…
There is no single mechanism by which fast particles are accelerated in astrophysical environments, and it is now recognized that the data require a rich variety of different mechanisms operating under different conditions. The mechanisms…
The bipolar, nonthermal, high-latitude lobes known as the Fermi bubbles (FBs) are thought to originate from a massive energy release near the Galactic centre (GC). We constrain the FB engine and the circumgalactic medium (CGM) by…
Imagine a swarm of free particles near a point P outside a gravitating mass M and a free reference particle at P that is on a radial escape trajectory away from M. Relative to this reference particle and in a Fermi normal coordinate system…
We introduce a simple stochastic system able to generate anomalous diffusion both for position and velocity. The model represents a viable description of the Fermi's acceleration mechanism and it is amenable to analytical treatment through…
In the present work, we start from a minimal Hamiltonian for Fermi systems where the s-wave scattering is the only low energy constant at play. Many-Body Perturbative approach that is usually valid at rather low density is first discussed.…
We consider a disordered system of gapless fermions interacting with a singular transverse (2+1)-dimensional gauge-field. We study quantum corrections to fermion conductivity and show that they are very different from those in a Fermi…