Moduli Oscillation Induced by Reheating

Understand

We estimate the abundance of the coherent oscillation of moduli, which linearly couple to matter fields through higher dimensional operators.

• During the (p)reheating after inflation, matter particles are efficiently produced and it can affect the moduli potential in a non-adiabatic way, which results in the coherent oscillation of the moduli.
• In particular, such effects are most important at the very beginning of the (p)reheating.
• It is found that this production mechanism is so efficient that a successful evolution of the universe can be threatened even if the moduli mass is larger than the Hubble scale.