Nonlinear Perturbations in a Variable Speed of Light Cosmology
  A variable speed of light (VSL) cosmology is described in which the causal
mechanism of generating primordial perturbations is achieved by varying the
speed of light in a primordial epoch. This yields an alternative to inflation
for explaining the formation of the cosmic microwave background (CMB) and the
large scale structure (LSS) of the universe. We make use of the $\delta{\cal
N}$ formalism to identify signatures of primordial nonlinear fluctuations, and
this allows the VSL model to be distinguished from inflationary models. In
particular, we find that the parameter $f_{\rm NL}=5$ in the variable speed of
light cosmology. The value of the parameter $g_{\rm NL}$ evolves during the
primordial era and shows a running behavior.
