相关论文: Modeling the Saturation of the Bell Instability us…
The filamentation (Weibel) instability plays a key role in the formation of collisionless shocks which are thought to produce Gamma-Ray-Bursts and High-Energy-Cosmic-Rays in astrophysical environments. While it has been known for long that…
We use particle-in-cell (PIC) simulations of a collisionless, electron-ion plasma with a decreasing background magnetic field, $B$, to study the effect of velocity-space instabilities on the viscous heating and thermal conduction of the…
Slow dynamical changes in magnetic-field strength and invariance of the particles' magnetic moments generate ubiquitous pressure anisotropies in weakly collisional, magnetized astrophysical plasmas. This renders them unstable to fast,…
The dynamics of a binary neutron stars merger is governed by physics under the most extreme conditions, including strong spacetime curvature, ultra-high matter densities, luminous neutrino emission and the rapid amplification of the initial…
Using a multi-fluid approach, we investigate streaming and thermal instabilities of the electron-ion plasma with homogeneous cold cosmic rays propagating perpendicular to the background magnetic field. Perturbations are considered to be…
A large set of numerical simulations of magnetohydrodynamic (MHD) turbulence induced by the magnetorotational instability (MRI) is presented. Revisiting the previous survey conducted by Sano et al. (2004), we investigate the gas pressure…
The magnetic Rayleigh-Taylor instability has been shown to play a key role in many astrophysical systems. The equation for the growth rate of this instability in the incompressible limit, and the most-unstable mode that can be derived from…
This research was motivated by the recent observations indicating very strong magnetic fields at some supernova remnant shocks, which suggests in-situ generation of magnetic turbulence. The dissertation presents a numerical model of…
Previous studies of the nonlinear regime of the magnetorotational instability in one particular type of shearing box model -- unstratified with no net magnetic flux -- find that without explicit dissipation (viscosity and resistivity) the…
We present numerical simulations of driven magnetohydrodynamic (MHD) turbulence with weak/moderate imposed magnetic fields. The main goal is to clarify dynamics of magnetic field growth. We also investigate the effects of the imposed…
Turbulent motion driven by the magnetorotational instability (MRI) is believed to provide an anomalous viscosity strong enough to account for observed accretion rates in protostellar accretion disks. In the first of two papers, we perform…
Relativistic magnetized jets, such as those from AGN, GRBs and XRBs, are susceptible to current- and pressure-driven MHD instabilities that can lead to particle acceleration and non-thermal radiation. Here we investigate the development of…
The magnetorotational instability (MRI) is considered a leading mechanism for driving angular momentum transport in differentially rotating astrophysical flows, including accretion disks and protoneutron stars. This process is mediated by…
(abridged) The ICM has been suggested to be buoyantly unstable in the presence of magnetic field and anisotropic thermal conduction. We perform first cosmological simulations of galaxy cluster formation that simultaneously include magnetic…
Low-frequency axial oscillations (5-50 kHz) stand out as a pervasive feature observed in many types of Hall thrusters. While it is widely recognized that the ionization effects play the central role in this mode, as manifested via the large…
The relationship between a decaying strong turbulence and the mirror instability in a slowly expanding plasma is investigated using two-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular…
Cosmic ray propagation in the Milky Way and other galaxies is largely diffusive, with mean free path determined primarily by pitch angle scattering from hydromagnetic waves with wavelength of order the cosmic ray gyroradius. In the theory…
This paper continues a series reporting different aspects of the behaviour of disc galaxy simulations that support spiral instabilities. The focus in this paper is to demonstrate how linear spiral instabilities saturate and decay, and how…
The saturation of ion cyclotron Alfven turbulence excited by beam particles is investigated using resonance broadening theory. The stochastic scattering which decorrelates particles, includes both random acceleration by electric fields and…
Interactions between magnetic fields advected by matter play a fundamental role in the Universe at a diverse range of scales. A crucial role these interactions play is in making turbulent fields highly anisotropic, leading to observed…