Preheating with higher dimensional interaction
  Particle production caused by the oscillation after inflation is important since it explains reheating after inflation. On the particle theory side, we know that effective action may have additional higher dimensional terms (usually called non-renormalizable terms) suppressed by the cut-off scale. Moreover, interaction between inflaton and so-called moduli field will be higher dimensional. Therefore, if such higher dimensional interaction is significant for resonant particle production, one cannot avoid the effect in preheating study. We explicitly calculated the required number of oscillation for the energy transfer. Consequently, cosmological history of an oscillating field and the moduli problem can be reconsidered. 
Seishi Enomoto, Nobuhiro Maekawa, Tomohiro Matsuda
hep-ph astro-ph.CO hep-th