The Effect of Local non-Gaussianity on the Matter Bispectrum at Small
  Scales
  We compute the matter bispectrum in the presence of primordial local
non-Gaussianity over a wide range of scales, including the very small nonlinear
ones. We use the Halo Model approach, considering non-Gaussian corrections to
the halo profiles, the halo mass function and the bias functions. We compare
our results in the linear and mildly nonlinear scales to a large ensemble of
Gaussian and non-Gaussian numerical simulations. We consider both squeezed and
equilateral configurations, at redshift z = 0 and z = 1. For z = 0, the
deviations between the Halo Model and the simulations are smaller than 10% in
the squeezed limit, both in the Gaussian and non-Gaussian cases. The Halo Model
allows to make predictions on scales much smaller than those reached by
numerical simulations. For local non-Gaussian initial conditions with a
parameter fNL = 100, we find an enhancement of the bispectrum in the squeezed
configuration k = k3 = k2 >> k1 \sim 0.01 h^{-1} Mpc, of \sim 15% and \sim 25%
on scales k \sim 1 h^{-1} Mpc, at z = 0 and z = 1 respectively. This is mainly
due to the non-Gaussian corrections in the linear bias. Finally we provide a
very simple expression valid for any scenario, i.e. for any choice of the halo
profile, mass and bias functions, which allow for a fast evaluation of the
bispectrum on squeezed configurations.
