Magnetic Fields in the Aftermath of Phase Transitions

The COSLAB effort has focussed on the formation of topological defects during phase transitions. Yet there is another potentially interesting signature of cosmological phase transitions, which also deserves study in the lab. This is the generation of magnetic fields during phase transitions. In particular, cosmological phase transitions that also lead to preferential production of matter over antimatter (``baryogenesis''), are expected to produce helical (left-handed) magnetic fields. The study of analogous processes in the lab can yield important insight into the production of helical magnetic fields, and the observation of such fields in the universe can be invaluable for both particle physics and cosmology.Comment: 9 pages. Contribution to the Royal Society Discussion Meeting ``Cosmology Meets Condensed Matter'', January 28-29, 200