  The Standard Model Higgs boson, which has previously been shown to develop an
effective vacuum expectation value during inflation, can give rise to large
particle masses during inflation and reheating, leading to temporary blocking
of the reheating process and a lower reheat temperature after inflation. We
study the effects on the multiple stages of reheating: resonant particle
production (preheating) as well as perturbative decays from coherent
oscillations of the inflaton field. Specifically, we study both the cases of
the inflaton coupling to Standard Model fermions through Yukawa interactions as
well as to Abelian gauge fields through a Chern-Simons term. We find that, in
the case of perturbative inflaton decay to SM fermions, reheating can be
delayed due to Higgs blocking and the reheat temperature can decrease by up to
an order of magnitude. In the case of gauge-reheating, Higgs-generated masses
of the gauge fields can suppress preheating even for large inflaton-gauge
couplings. In extreme cases, preheating can be shut down completely and must be
substituted by perturbative decay as the dominant reheating channel. Finally,
we discuss the distribution of reheat temperatures in different Hubble patches,
arising from the stochastic nature of the Higgs VEV during inflation and its
implications for the generation of both adiabatic and isocurvature
fluctuations.
