Ambipolar diffusion and anisotropy of resistivity in neutron star cores

Abstract

Evolution of the magnetic field in neutron star cores depends on the properties of matter above nuclear density. The present paper considers drift and dissipative processes which determine evolution of the magnetic field in the core region. The generalized Ohm's law is derived assuming that all species of particles are in the normal (non-superfluid) state. We discuss in detail a possible influence of the considered processes on the field decay. Probably the most important of these processes is dissipation due to the enhancement of the resistivity in strong magnetic fields. Drift phenomena associated with the partial pressure gradients, however, can also strongly influence evolution of the field. These phenomena are of particular importance if there is no chemical equilibrium in npe-plasma.