A mean field Ohm's law for collisionless plasmas

Abstract

A mean field Ohm’s law valid for collisionless plasmas is derived kinetically. It is shown that contrary to conventional thinking, the resulting hyperresistivity is significantly smaller than its fluid counterpart due to the fact that the turbulent decorrelation rate is linked to the rapid electron ballistic motion rather than the slower nonlinear mixing time. Moreover, the off‐diagonal contributions to the parallel electron momentum flux are shown to result in Ohm’s law renormalizations that dwarf the current diffusivity and break radial parity symmetry.