Lepton asymmetries and primordial hypermagnetic helicity evolution
  The hypermagnetic helicity density at the electroweak phase transition (EWPT)
exceeds many orders of magnitude the galactic magnetic helicity density.
Together with previous magnetic helicity evolution calculations after the EWPT
and hypermagnetic helicity conversion to the magnetic one at the EWPT, the
present calculation completes the description of the evolution of this
important topological feature of cosmological magnetic fields. It suggests that
if the magnetic field seeding the galactic dynamo has a primordial origin, it
should be substantially helical. This should be taken into account in scenarios
of galactic magnetic field evolution with a cosmological seed.
