Compressible hydromagnetic nonlinearities in the predecoupling plasma

A Two -Step Modification toward Implementing Compressible Source Terms in Low Compressible Flows

Hydromagnetic Turbulence

Recent progress in astrophysical hydromagnetic turbulence is being reviewed. The physical ideas behind the now widely accepted Goldreich–Sridhar model and its extension to compressible magnetohydrodynamic turbulence are introduced. Implications for cosmic ray diffusion and acceleration is being discussed. Dynamo-generated magnetic fields with and without helicity are contrasted against each oth...

Hydromagnetic turbulence in computer simulations

Hydromagnetic processes play an important role in many astrophysical systems (e.g. stars, galaxies, accretion discs). This is because the medium is hot enough to be partially or fully ionized. Because of the huge scales involved the medium is usually turbulent, provided there is an instability (shear, convection) facilitating the cascading of energy down to small scales. In turbulence research ...

Turbulent transport in hydromagnetic flows

The predictive power of mean-field theory is emphasized by comparing theory with simulations under controlled conditions. The recently developed test-field method is used to extract turbulent transport coefficients both in the kinematic and the nonlinear or quasi-kinematic cases. A striking example of the quasi-kinematic method is provided by magnetic buoyancy-driven flows that produce an α eff...

Astrophysical Hydromagnetic Turbulence

Recent progress in astrophysical hydromagnetic turbulence is being reviewed. The physical ideas behind the now widely accepted Goldreich–Sridhar model and its extension to compressible magnetohydrodynamic turbulence are introduced. Implications for cosmic ray diffusion and acceleration is being discussed. Dynamo-generated magnetic fields with and without helicity are contrasted against each oth...