ABSTRACT
The reheating temperature is the temperature of radiation at the onset of the radiation era of the Hot Big Bang. Perturbative reheating corresponds to the decay of individual inflaton particles making up the oscillating inflaton condensate. A fraction of the inflaton energy always survives preheating, and the inflaton field continues oscillating until it decays perturbatively. In the inflationary paradigm where inflation is due to a homogeneous scalar field, reheating occurs because the inflaton field decays into the particles of the thermal bath of the Hot Big Bang. The experimental confirmation that fundamental scalar fields exist makes it more credible that such a scalar field is also behind dark energy, especially in the early Universe, where the existing fundamental theories consider a multitude of scalar fields. Solutions to the Klein-Gordon equation can be shown to converge in time in an attractor solution, when the scalar field dominates the Universe.
