Warm inflation in the presence of magnetic fields
  We study the effects of primordial magnetic fields on the inflationary potential in the context of a warm inflation scenario. The model, based on global supersymmetry with a new-inflation-type potential and a coupling between the inflaton and a heavy intermediate superfield, is already known to preserve the flatness required for slow-roll conditions even after including thermal contributions. Here we show that the magnetic field makes the potential even flatter, retarding the transition and rendering it smoother. 
Gabriella Piccinelli, Angel Sanchez, Alejandro Ayala and Ana Julia   Mizher
hep-ph astro-ph.CO