Magnetohydrodynamic Equations in a Gravitational Field and Excitation of   Magnetohydrodynamic Shock Waves by a Gravitational Wave
  On the basis of simple principles we derive and investigate the equations of relativistic plasma magnetohydrodynamics (MHD) in an arbitrary gravitational field. An exact solution describing the motion of magnetoactive plasma against the background of the metric of a plane gravitational wave (PGW) with an arbitrary amplitude is obtained. It is shown that in strong magnetic fields even a sufficiently small amplitude PGW can create a shock MHD wave, propagating at a subluminal velocity. Astrophysical consequences of the anomalous plasma acceleration are considered. 
Yu.G. Ignatyev
gr-qc astro-ph.HE