Magnetic Helicity in Sphaleron Debris
  We develop an analytical technique to evaluate the magnetic helicity in the debris from sphaleron decay. We show that baryon number production leads to left-handed magnetic fields, and that the magnetic helicity is conserved at late times. Our analysis explicitly demonstrates the connection between sphaleron-mediated cosmic baryogenesis and cosmic magnetogenesis. 
Yi-Zen Chu, James B. Dent and Tanmay Vachaspati
hep-th astro-ph.CO hep-ph