Ohmic currents induced prior to decoupling are investigated in a standard
transport model accounting both for the expansion of the background geometry as
well as of its relativistic inhomogeneities. The relative balance of the Ohmic
electric fields in comparison with the Hall and thermoelectric contributions is
specifically addressed. The impact of the Ohmic currents on the evolution of
curvature perturbations is discussed numerically and it is shown to depend
explicitly upon the evolution of the conductivity.Comment: 8 pages, 4 included figure