Related papers: Diffusion of cosmic rays in MHD turbulence
Diffusion of cosmic rays (CRs) is the key process of understanding their propagation and acceleration. We employ the description of spatial separation of magnetic field lines in MHD turbulence in Lazarian & Vishniac (1999) to quantify the…
The interaction of cosmic rays (CRs) with magnetic fields and the interstelar medium (ISM) leads to the production of nonthermal radiation. Although this has been a topic of study for many years, it still poses many challenges to the…
Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to obtain the scattering frequency for…
Pitch-angle scattering rates for cosmic-ray particles in magnetohydrodynamic (MHD) simulations with imbalanced turbulence are calculated for fully evolving electromagnetic turbulence. We compare with theoretical predictions derived from the…
Recent gamma-ray observations reveal inhomogeneous diffusion of cosmic rays (CRs) in the interstellar medium (ISM). This is expected as the diffusion of CRs depends on the properties of turbulence, which can vary widely in the multi-phase…
We study the scattering of low-energy Cosmic Rays (CRs) in a turbulent, compressive MHD fluid. We show that compressible MHD modes -- fast or slow waves with wave lengths smaller than CR mean free paths induce cyclotron instability in CRs.…
In a weakly compressible high-$\beta$ medium, pitch-angle scattering and the associated scattering acceleration of cosmic rays (CRs) by anisotropic Alfv\'{e}n and slow modes of magnetohydrodynamic (MHD) turbulence is inefficient. To tap the…
The transport of cosmic rays (CRs) is crucial for the understanding of almost all high-energy phenomena. Both pre-existing large-scale magnetohydrodynamic (MHD) turbulence and locally generated turbulence through plasma instabilities are…
A detailed understanding of cosmic-ray transport in galactic halos is essential for explaining various observations, such as the radio continuum measurements of synchrotron radiation from energetic electrons. Of central importance is the…
Cosmic rays (CRs) interact with turbulent magnetic fields in the intestellar medium, generating nonthermal emission. After many decades of studies, the theoretical understanding of their diffusion in the ISM continues to pose a challenge.…
The nature of cosmic ray (CR) transport in the Milky Way remains elusive. The predictions of current micro-physical CR transport models in magneto-hydrodynamic (MHD) turbulence are drastically different from what is observed. These models…
Cosmic rays scatter off magnetic irregularities (Alfven waves) with which they are resonant, that is waves of wavelength comparable to their gyroradii. These waves may be generated either by the cosmic rays themselves, if they stream faster…
Cosmic-ray (CR) diffusion is the result of the interaction of such charged particles against magnetic fluctuations. These fluctuations originate from large-scale turbulence cascading towards smaller spatial scales, decomposed into three…
Cosmic rays (CRs) are an important source of feedback in a variety of astrophysical contexts. Magneto-hydrodynamical (MHD) simulations treating CRs as a fluid have shown that how their feedback operates is strongly dependent on their…
Owing to the complexity of turbulent magnetic fields, modeling the diffusion of cosmic rays is challenging. Based on the current understanding of anisotropic magnetohydrodynamic (MHD) turbulence, we use test particles to examine the cosmic…
The diffusion of galactic cosmic rays (CR) is considered. It is anticipated that the nonlinear MHD cascade sets the power-law spectrum of turbulence from the principle scale 100 pc to much smaller scales. We found that the dissipation of…
Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a…
We revisit propagation of galactic cosmic rays (CRs) in light of recent advances in CR diffusion theory in realistic interstellar turbulence. We use a tested model of turbulence in which it has been shown that fast modes dominate scattering…
Recent years have seen many arguments for cosmic rays (CRs) as an important influence on galactic and circumgalactic (CGM) physics, star and galaxy formation. We present a pedagogical overview of state-of-the-art modeling of…
Cosmic rays (CRs) play a pivotal role in various astrophysical systems, delivering feedback over a broad range of scales. However, modeling CR transport remains challenging due to its inherently multi-scale nature and complex microphysics.…