Primordial magnetic fields induced by cosmological particle creation

We study the primordial magnetic field generated by stochastic currents produced by scalar charged particles created at the beginning of the radiation dominated epoch. We find that, for the mass range ${10}^{-6}\hspace{0.5em}\mathrm{GeV}\lesssim m\lesssim {10}^2\hspace{0.5em}\mathrm{GeV}$, a field of sufficient intensity to seed different mechanisms of galactic magnetic field generation, while still consistent with observational and theoretical constraints, is created coherently over a galactic scale.