Observational signatures of Higgs inflation
  We investigate the dependency of Higgs inflation on the non-renormalisable
matching between the low energy Standard Model limit and the inflationary
regime at high energies. We show that for the top mass range $m_t \gtrsim
171.8$ GeV the scenario robustly predicts the spectral index $n_s \simeq 0.97$
and the tensor-to-scalar ratio $r\simeq 0.003$. The matching is however
non-trivial, even the best-fit values $m_h=125.09$ GeV and $m_t=173.21$ GeV
require a jump $\delta \lambda \sim 0.01$ in the Higgs coupling below the
inflationary scale. For $m_t\lesssim 171.8$ GeV, the matching may generate a
feature in the inflationary potential. In this case the predicted values of
$n_s$ and $r$ vary but the model is still falsifiable. For example, a detection
of negative running of spectral index at level $\alpha_s \lesssim -0.01$ would
rule out Higgs inflation.
