Mild quasi-local non-Gaussianity as a signature of modified gravity
  during inflation
  We show that modifications of Einstein gravity during inflation could leave
potentially measurable imprints on cosmological observables in the form of
non-Gaussian perturbations. This is due to the fact that these modifications
appear in the form of an extra field that could have non-trivial interactions
with the inflaton. We show it explicitly for the case $R+\alpha R^2$, where
nearly scale-invariant non-Gaussianity at the level of $f_{\rm NL} \approx -(1$
to $30)$ can be obtained, in a quasi-local configuration.
