Preheating the Universe from the Standard Model Higgs
  We discuss Preheating after an inflationary stage driven by the Standard
Model (SM) Higgs field non-minimally coupled to gravity. We find that
Preheating is driven by a complex process in which perturbative and
non-perturbative effects occur simultaneously. The Higgs field, initially an
oscillating coherent condensate, produces non-perturbatively W and Z gauge
fields. These decay very rapidly into fermions, thus preventing gauge bosons to
accumulate and, consequently, blocking the usual parametric resonance. The
energy transferred into the fermionic species is, nevertheless, not enough to
reheat the Universe, and resonant effects are eventually developed. Soon after
resonance becomes effective, also backreaction from the gauge bosons into the
Higgs condensate becomes relevant. We have determined the time evolution of the
energy distribution among the remnant Higgs condensate and the non-thermal
distribution of the SM fermions and gauge fields, until the moment in which
backreaction becomes important. Beyond backreaction our approximations break
down and numerical simulations and theoretical considerations beyond this work
are required, in order to study the evolution of the system until
thermalization.
