Gas distribution, metal enrichment, and baryon fraction in Gaussian and
  non-Gaussian universes
  We study the cosmological evolution of baryons in universes with and without
primordial non-Gaussianities via (large scale) N-body/hydrodynamical
simulations, including gas cooling, star formation, stellar evolution, chemical
enrichment from both population III and population II regimes, and feedback
effects. We find that large fnl values for non-Gaussianities can alter the gas
probability distribution functions, the metal pollution history, the halo
baryon, gas and stellar fractions, mostly at early times. More precisely: (i)
non-Gaussianities lead to an earlier evolution of primordial gas, structures,
and star formation; (ii) metal enrichment starts earlier (with respect to the
Gaussian scenario) in non-Gaussian models with larger fnl; (iii) gas fractions
within the haloes are not significantly affected by the different values of
fnl, with deviations of ~1-10%; (iv) the stellar fraction is quite sensitive to
non-Gaussianities at early times, with discrepancies reaching up to a factor of
~10 at very high z, and rapidly converging at low z; (v) the trends at low
redshift are independent from fnl: they are mostly led by the ongoing baryonic
evolution and by the feedback mechanisms, which determine a ~25%-30%
discrepancy in the baryon fraction of galaxy groups/clusters with respect to
the cosmic values; (vi) non-Gaussianity impacts on the cluster X-ray emission
or on the SZ effect(s) are expected to be not very large and dominated by
feedback mechanisms, whereas some effects on the 21-cm emission can be expected
at early times; (vii) in order to address non-Gaussianities in the cosmological
structure contest, high-redshift (z~10) investigations are required: first
stars, galaxies, quasars, and GRBs may be potential cosmological probes of
non-Gaussianities.
