  This work is a supplement on the previous research about primordial
electromagnetic fields. In this work, three important problems are discussed:
the evolution of primordial electric fields, the electric and particle
densities' solitons in plasma before recombination and their influences on the
power spectra of cosmic microwave background. Detailed computations show that
the primordial electric fields dissipate by Landau damping effect on both large
scale and small scale and there is no impact on the spectrum. While, before
recombination, there exist solitary waves stably propagating in plasma whose
speed is significantly slower than that of baryonic acoustic oscillations,
working only at extremely small scale. On the other hand, the amplitude of
solitons is so weak that only a significantly small contribution on the phase
of baryon acoustic oscillations, so there merely exist the messages about such
electric solitary waves on the spectrum. In a word, as relevant monographs on
cosmology, neglecting the electromagnetic fields (electric fields at least) is
a reasonable treatment on the calculations of cosmic microwave background.
However, the protonic density fluctuations show a form of KdV equation while
its propagation as a stable solitary wave, leading a probability to the origin
of fluctuation promoting the generation and evolution of galaxies.
