The Standard Model Higgs as the origin of the hot Big Bang
  If the Standard Model (SM) Higgs is weakly coupled to the inflationary
sector, the Higgs is expected to be universally in the form of a condensate
towards the end of inflation. The Higgs decays rapidly after inflation - via
non-perturbative effects - into an out-of-equilibrium distribution of SM
species, which thermalize soon afterwards. If the post-inflationary equation of
state of the universe is stiff, $w \simeq +1$, the SM species eventually
dominate the total energy budget. This provides a natural origin for the
relativistic thermal plasma of SM species, required for the onset of the `hot
Big Bang' era. The viability of this scenario requires the inflationary Hubble
scale $H_*$ to be lower than the instability scale for Higgs vacuum decay, the
Higgs not to generate too large curvature perturbations at cosmological scales,
and the SM dominance to occur before Big Bang Nucleosynthesis. We show that
successful reheating into the SM can only be obtained in the presence of a
non-minimal coupling to gravity $\xi \gtrsim 1$, with a reheating temperature
of $T_{\rm RH} \gtrsim \mathcal{O}(10^{10})\xi^{3/2}(H_*/10^{14}{\rm
GeV})^2~{\rm GeV}$.
