Testing primordial non-Gaussianities on galactic scales at high redshift
  Primordial non-Gaussianities provide an important test of inflationary
models. Although the Planck CMB experiment has produced strong limits on
non-Gaussianity on scales of clusters, there is still room for considerable
non-Gaussianity on galactic scales. We have tested the effect of local
non-Gaussianity on the high redshift galaxy population by running five
cosmological N-body simulations down to z=6.5. For these simulations, we adopt
the same initial phases, and either Gaussian or scale-dependent non-Gaussian
primordial fluctuations, all consistent with the constraints set by Planck on
clusters scales. We then assign stellar masses to each halo using the halo -
stellar mass empirical relation of Behroozi et al. (2013). Our simulations with
non-Gaussian initial conditions produce halo mass functions that show clear
departures from those obtained from the analogous simulations with Gaussian
initial conditions at z>~10. We observe a >0.3 dex enhancement of the low-end
of the halo mass function, which leads to a similar effect on the galaxy
stellar mass function, which should be testable with future galaxy surveys at
z>10. As cosmic reionization is thought to be driven by dwarf galaxies at high
redshift, our findings may have implications for the reionization history of
the Universe.
