title: Estimate of the primordial magnetic field helicity.
abstract: Electroweak baryogenesis proceeds via changes in the non-Abelian Chern-Simons number. It is argued that these changes generate a primordial magnetic field with left-handed helicity. The helicity density of the primordial magnetic field today is then estimated to be given by approximately 10(2)n(b), where n(b) approximately 10(-6)/cm(3) is the present cosmological baryon number density. With certain assumptions about the inverse cascade we find that the field strength at recombination is approximately 10(-13) G on a comoving coherence scale approximately 0.1 pc.
authors.affiliation: Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
authors.forename: T
authors.initials: T
authors.lastname: Vachaspati