STABILITY OF ELECTRICALLY CONDUCTING, ROTATING FLUID IN THE PRESENCE OF A HORIZONTAL MAGNETIC FIELD.

The problem of the hydromagnetic stability of conducting fluid of variable density plays an important role in the study of astrophysics (theories and sunspot magnetic fields, beating of solar corona, stability of the steller atmosphere in magnetic field). Since in astrophysical problems the coriolis forces play an important role, it is necessary to study the combined effect of rotation and magnetic field. In a more realistic physical situation specially relevant to the problem of confinement of matter one must take into account the finite resistivity of the medium. The Rayleigh instability of an incompressible, finitely conducting, inviscid fluid of variable density is investigated under the influence of a horizontal magnetic field. Due to the finite conducting of the fluid, it is found that a potentially stable or unstable configuration retains its character. It may further be noted that the stratification can be stabilized for a certain wavenumber range in the absence of finite resistivity. The effect of finite resistivity is to wipe out the aforesaid range of the wavenumber for which the system is stabilized otherwise.