Ye. Lyubarskii, ON THE ELECTRIC-CURRENT DISTRIBUTION IN POYNTING-DOMINATED OUTFLOWS, Monthly Notices of the Royal Astronomical Society, 285(3), 1997, pp. 604-606
An ultrarelativistic wind generated by a rotating, strongly magnetized
object (neutron star, accretion disc or black hole) is considered. It
is shown that the self-consistent solution requires a singular electr
ic current to flow along the axis of symmetry.