Non-Gaussian Enhancements of Galactic Halo Correlations in Quasi-Single
  Field Inflation
  We consider a quasi-single field inflation model in which the inflaton
interacts with a massive scalar field called the isocurvaton. Due to the
breaking of time translational invariance by the inflaton background, these
interactions induce kinetic mixing between the inflaton and isocurvaton, which
is parameterized by a constant $\mu$. We derive analytic formulae for the
curvature perturbation two-, three-, four-, five-, and six-point functions
explicitly in terms of the external wave-vectors in the limit where $\mu$ and
the mass of the isocurvaton $m$ are both much smaller than $H$. In previous
work, it has been noted that when $m/H$ and $\mu/H$ are small, the
non-Gaussianities predicted by quasi-single field inflation give rise to long
wavelength enhancements of the power spectrum for biased objects (e.g.,
galactic halos). We review this calculation, and calculate the analogous
enhanced contribution to the bispectrum of biased objects. We determine the
scale at which these enhanced terms are larger than the Gaussian piece. We also
identify the scaling of these enhanced parts to the $n$-point function of
biased objects.
