We report a new finite-difference scheme for two-dimensional magnetohydrodynamics (MHD) simulations, with and without rotation, in unstructured grids with quadrilateral cells. The new scheme is implemented within the code VULCAN/2D, which already includes radiation-hydrodynamics in various approximations and can be used with arbitrarily moving meshes (ALE). The MHD scheme, which consists of cel...

Adopting the theoretical framework for the generalized fishbonelike dispersion relation, an extended hybrid magnetohydrodynamics gyrokinetic simulation model has been derived analytically by taking into account both thermal ion compressibility and diamagnetic effects in addition to energetic particle kinetic behaviors. The extended model has been used for implementing an extended version of hyb...

The COAST (for Computational Astrophysics) project is a program of massively parallel numerical simulations in astrophysics involving astrophysicists and software engineers from CEA/IRFU Saclay. The scientific objective is the understanding of the formation of structures in the Universe, including the study of largescale cosmological structures and galaxy formation, turbulence in interstellar m...

Magnetohydrodynamic (MHD) waves are analysed in the early Universe, in the inflationary era, assuming the Universe to be filled with a nonviscous fluid of the Zel’dovich type (p = ρ) in a metric of the de Sitter form. A spatially uniform, time dependent, magnetic field B0 is assumed to be present. The Einstein equations are first solved to give the time dependence of the scale factor, assuming ...

This paper presents an overview and introduction to Smoothed Particle Hydrodynamics and Magnetohydrodynamics in theory and in practice. Firstly, we give a basic grounding in the fundamentals of SPH, showing how the equations of motion and energy can be self-consistently derived from the density estimate. We then show how to interpret these equations using the basic SPH interpolation formulae an...