Resolving primordial physics through correlated signatures
  We discuss correlations among spectral observables as a new tool for
differentiating between models for the primordial perturbation. We show that if
generated in the isocurvature sector, a running of the scalar spectral index is
correlated with the statistical properties of non-Gaussianities. In particular,
we find a large running will inevitably be accompanied by a large running of
$f_{\rm NL}$ and enhanced $g_{\rm NL}$, with $g_{\rm NL}\gg f_{\rm NL}^2$. If
the tensor to scalar ratio is large, a large negative running must turn
positive on smaller scales. Interestingly, the characteristic scale of the
transition could potentially distinguish between the inflaton and isocurvature
fields.
