Related papers: Cosmic rays density fluctuations with turbulence u…
Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\tilde B/\langle B\rangle \sim 1$ is present on top of the mean field gradient,…
Cosmic rays (CRs) are dynamically important for the formation and evolution of galaxies by regulating star formation and by powering galactic outflows. However, to what extent CRs regulate galaxy formation depends on the coupling strength…
While it is well-known that cosmic rays (CRs) can gain energy from turbulence via second order Fermi acceleration, how this energy transfer affects the turbulent cascade remains largely unexplored. Here, we show that damping and steepening…
We study dynamical effects of cosmics rays (CRs) on the thermal instability in the linear regime. CRs and the thermal plasma are treated as two different interacting fluids, in which CRs can diffuse along the magnetic field lines. We show…
The nature of solar wind turbulence at large scale is rather well understood in the theoretical framework of magnetohydrodynamics. The situation is quite different at sub-proton scales where the magnetic energy spectrum measured by…
We introduce a novel diffusion model for the propagation of cosmic rays (CRs) that incorporates an anisotropic diffusion tensor of a general form within a realistically modeled large-scale Galactic magnetic field. The parameters of the…
Cosmic rays (CRs) are a plausible mechanism for launching winds of cool material from the discs of star-forming galaxies. However, there is no consensus on what types of galaxies likely host CR-driven winds, or what role these winds might…
Cosmic rays (CR) propagate through the galactic scales down to the smaller scales at which stars form. CRs are close to energy equipartition with the other components of the interstellar medium and can provide a support against gravity if…
The solar wind is a magnetized and turbulent plasma. Its turbulence is often dominated by Alfv\'enic fluctuations and often deemed as nearly incompressible far away from the Sun, as shown by in-situ measurements near 1AU. However, for solar…
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…
One of the unsolved problems in cosmic ray (CR) physics is the small radial gradient of the gamma-ray intensity compared to the inferred CR source distribution in the Galactic disk. In diffusive CR propagation models the most natural…
The macroscopic behavior of dense suspensions of neutrally-buoyant spheres in turbulent plane channel flow is examined. We show that particles larger than the smallest turbulence scales cause the suspension to deviate from the continuum…
Understanding the transport of energetic cosmic rays belongs to the most challenging topics in astrophysics. Diffusion due to scattering by electromagnetic fluctuations is a key process in cosmic-ray transport. The transition from a…
Small scale challenges suggest some missing pieces in our understanding of dark matter. A cascade theory for dark matter is proposed to provide extra insights, similar to the cascade phenomenon in hydrodynamic turbulence. The kinetic energy…
Turbulence, ubiquitous in nature and across various systems, exhibits chaotic and intermittent fluctuations in space and time, defying precise prediction. For nearly a century, extensive efforts have been made to uncover the underlying…
The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…
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.…
We derive the exact relation for the energy transfer in three-dimensional compressible two-fluid plasma turbulence. In the long-time limit, we obtain an exact law which expresses the scale-to-scale average energy flux rate in terms of two…
In rapidly rotating turbulence (Rossby number much less than unity), the standard mixing length theory for turbulent convection breaks and Coriolis force enters the force balance such that magnetic field eventually depends on rotation. By…
The interplanetary magnetic fluctuation spectrum obeys a Kolmogorovian power law at scales above the proton inertial length and gyroradius which is well regarded as an inertial range. Below these scales a power law index around $-2.5$ is…