Modified magnetohydrodynamics model with wave turbulence: astrophysical applications

Modeling astrophysical flows in the framework of classical magnetohydrodynamics often encounters significant difficulties due to high (up to relativistic) Alfv$\rm \acute e$n wave velocities. Such situations can arise in modeling the magnetosphere of planets and stars and accretion flows in polars, intermediate polars, and near-neutron stars. In a strongly magnetized plasma, wave turbulence can develop, which can significantly affect the energy balance and the forces determining the plasma dynamics. In this paper, a closed system of equations is obtained for modified magnetohydrodynamics with wave turbulence for a wide range of magnetic fields and turbulence energies. The turbulent flow is described as the sum of the mean flow and perturbations induced by relativistic Alfv$\rm \acute e$n waves. Expressions are derived for the turbulence-induced body force, viscosity, and dissipative heating. An analysis of equations in certain limit cases is performed. It is shown that the proposed approach can be used for modeling a broad class of astrophysical plasma flows.