Magnetic Fields from the Electroweak Phase Transition
  I review some of the mechanisms through which primordial magnetic fields may be created in the electroweak phase transition. I show that no magnetic fields are produced initially from two-bubble collisions in a first-order transition. The initial field produced in a three-bubble collision is computed. The evolution of fields at later times is discussed. 
Ola Tornkvist (Fermilab and DAMTP, Cambridge)