Non-Gaussianity of a single scalar field in general covariant
  Ho\v{r}ava-Lifshitz gravity
  In this paper, we study non-Gaussianity generated by a single scalar field in
slow-roll inflation in the framework of the non-relativistic general covariant
Ho\v{r}ava-Lifshitz theory of gravity with the projectability condition and an
arbitrary coupling constant $\lambda$, where $\lambda$ characterizes the
deviation of the theory from general relativity (GR) in the infrared. We find
that the leading effect of self-interaction, in contrary to the case of minimal
scenario of GR, is in general of the order $\hat{\alpha}_{n} \epsilon^{3/2}$,
where $\epsilon$ is a slow-roll parameter, and $\hat{\alpha}_{n} (n = 3, 5)$
are the dimensionless coupling coefficients of the six-order operators of the
Lifshitz scalar, and have no contributions to power spectra and indices of both
scalar and tensor. The bispectrum, comparing with the standard one given in GR,
is enhanced, and gives rise to a large value of the nonlinearity parameter
$f_{\text{NL}}$.We study how the modified dispersion relation with high order
moment terms affects the evaluation of the mode function and in turn the
bispectrum, and show explicitly that the mode function takes various asymptotic
forms during different periods of its evolution. In particular, we find that it
is in general of superpositions of oscillatory functions, instead of plane
waves like in the minimal scenario of GR. This results in a large enhancement
of the folded shape in the bispectrum.
