  The possible existence of a primordial magnetic field in the universe has
been previously investigated in many articles. Studies involving the influence
of a magnetic field in the nucleosyntesis era, studies considering the effects
in the formation of structures during the radiation era and the matter era have
been considered. We here assume the existence of a primordial magnetic field
and study its effect, in particular, in the formation of voids. The study is
twofold: to put constraints on the strength of the magnetic field during the
recombination era and to preview its effects on the formation of voids.
