We investigate the global large amplitude waves propagating across the solar disk as observed by the SOHO/Extreme Ultraviolet Imaging Telescope (EIT). These waves appear to be similar to those observed in H in the chromosphere and which are known as “Moreton waves,” associated with large solar flares [Moreton, 1960, 1964]. Uchida [1968] interpreted these Moreton waves as the propagation of a hy...

Electrostatic drift wave linear stability analysis is carried out for the Helimak configuration and compared against experimental data. Density fluctuation and cross-spectrum measurements show evidence of a coherent mode propagating perpendicular to the magnetic field which becomes unstable at k s 0.15. By comparing the experimental results with the wave characteristic of linear two-fluid theor...

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 ...

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 ...

Ultra-low-frequency (ULF) waves have been observed in the Mercury’s magnetosphere. In this work, Mariner-10 and MESSENGER high resolution magnetic field data are studied with wavelet analysis. Two ULF wave intervals have been selected: 29 March 1974 (Mariner-10) and 14 January 2008 (MESSENGER). Non-stationary oscillations, with strong amplitude and narrow bandwidth have been found. The Mariner-...

An approximate Riemann solver of Godunov type for ideal relativistic magnetohydrodynamic equations (RMHD) named as HLLC (“C” denotes contact) is developed. In HLLC the Riemann fan is approximated by two intermediate states, which are separated by the entropy wave. Numerical tests show that HLLC resolves contact discontinuity more accurately than the Harten-Lax-van Leer (HLL) method and an isola...

The one-dimensional oblique propagation of magnetohydrodynamic waves with arbitrary amplitudes in a Hall plasma with isotropic pressure is studied under assumption that the plasma β is large. It is shown that the wave evolution is described by the derivative nonlinear Schrödinger equation (DNLS).