  Extrapolating the Standard Model Higgs potential at high energies, we study
the barrier between the electroweak and Planck scale minima. The barrier arises
by taking the central values of the relevant experimental inputs, that is the
strong coupling constant and the top quark and Higgs masses. We then extend the
Standard Model by including a non-minimal coupling to gravity, and explore the
phenomenology of the Higgs inflation model. We point out that even
configurations that would be metastable in the Standard Model, become viable
for inflation if the non-minimal coupling is large enough to flatten the Higgs
potential at field values below the barrier; we find that the required value of
the non-minimal coupling is smaller than the one needed for the conventional
Higgs inflation scenario (which relies on a stable Standard Model Higgs
potential, without any barrier); in addition, values of the top mass which are
slightly larger than those required in the conventional scenario are allowed.
