Key points are not available for this paper at this time.
We study limits on a primordial magnetic field arising from cosmological data, including that from big bang nucleosynthesis, cosmic microwave background polarization plane Faraday rotation limits, and large-scale structure formation. We show that the physically-relevant quantity is the value of the effective magnetic field, and limits on it are independent of how the magnetic field was generated.
Kahniashvili et al. (Fri,) studied this question.