Force-free pulsar magnetosphere

In the steady, axisymmetric theory of the pulsar magnetosphere with the charge-separated plasma the critical field line separating the region of negative charge from the region of positive charge must be a straight line parallel to the equator owing to the rigidity of the pulsar surface. Thus, the theory with the complete charge separation yields an unphysical field structure for the dipole condition or the split monopole at the surface.