  It has been argued that electroweak baryogenesis generates a left-handed
primordial magnetic field. The helicity density of the primordial magnetic
field today is estimated to be $\sim 10^2 n_b$ where $n_b\sim 10^{-6}$ /cm$^3$
is the present cosmological baryon number density. With certain assumptions
about the inverse cascade the field strength at recombination is $\sim
10^{-13}$ G on a coherence scale $\sim 10^{-4}$ pc. Here I discuss the various
assumptions made in obtaining these estimates and the concomitant open issues.
