  According to the standard lore, a prolonged inflation leaves a quantum field
theory in a cold, low entropy state. Thus, some mechanism is needed to reheat
this post-inflationary state, leaving a hot, thermal, radiation-dominated
Universe. Typically, reheating is achieved coupling the inflaton field to the
QFT degrees of freedom. We argue that the nonequilibrium dynamics of a
non-conformal QFT in (post-)inflationary background space-time can produce hot
quark-gluon plasma with the reheating temperature of order the inflationary
Hubble scale, without the inflaton coupling.
