Non-Gaussianity from Lifshitz Scalar
  A Lifshitz scalar with the dynamical critical exponent z = 3 obtains
scale-invariant, super-horizon field fluctuations without the need of an
inflationary era. Since this mechanism is due to the special scaling of the
Lifshitz scalar and persists in the presence of unsuppressed self-couplings,
the resulting fluctuation spectrum can deviate from a Gaussian distribution. We
study the non-Gaussian nature of the Lifshitz scalar's intrinsic field
fluctuations, and show that primordial curvature perturbations sourced from
such field fluctuations can have large non-Gaussianity of order f_NL = O(100),
which will be detected by upcoming CMB observations. We compute the bispectrum
and trispectrum of the fluctuations, and discuss their configurations in
momentum space. In particular, the bispectrum is found to take various shapes,
including the local, equilateral, and orthogonal shapes. Intriguingly, all
integrals in the in-in formalism can be performed analytically.
