Palatini-Higgs inflation with non-minimal derivative coupling
  The predictions of standard Higgs inflation in the framework of the metric
formalism yield a tensor-to-scalar ratio $r \sim 10^{-3}$ which lies well
within the expected accuracy of near-future experiments $ \sim 10^{-4}$. When
the Palatini formalism is employed, the predicted values of $r$ get
highly-suppressed $r\sim 10^{-12}$ and consequently a possible non-detection of
primordial tensor fluctuations will rule out only the metric variant of the
model. On the other hand, the extremely small values predicted for $r$ by the
Palatini approach constitute contact with observations a hopeless task for the
foreseeable future. In this work, we propose a way to remedy this issue by
extending the action with the inclusion of a generalized non-minimal derivative
coupling term between the inflaton and the Einstein tensor of the form
$m^{-2}(\phi) G_{\mu\nu}\nabla^{\mu}\phi \nabla^{\nu}\phi$. We find that with
such a modification, the Palatini predictions can become comparable with the
ones obtained in the metric formalism, thus providing ample room for the model
to be in contact with observations in the near future.
