Infinite conductivity in general relativistic magnetohydrodynamics

Abstract

It is pointed out that in general relativistic magnetohydrodynamics Ohm's law does not determine the current density Ja in the limit of infinite conductivity, but that it is determined by the electromagnetic field equation as in nonrelativistic magnetohydrodynamics. It is also shown that the relation 2 omega .H= epsilon derived by Yodzis (1971) assuming Ja= epsilon ua for infinite conductivity, can also be obtained by a modified argument if the above view is taken.