Imprints of non-standard Dark Energy and Dark Matter Models on the 21cm
  Intensity Map Power Spectrum
  We study the imprint of non-standard dark energy (DE) and dark matter (DM)
models on the 21cm intensity map power spectra from high-redshift neutral
hydrogen (HI) gas. To this purpose we use halo catalogs from N-body simulations
of dynamical DE models and DM scenarios which are statistically
indistinguishable from the standard Cold Dark Matter model with Cosmological
Constant (LCDM) using currently available cosmological observations. We limit
our analysis to halo catalogs at redshift z = 1 and 2.3 which are common to all
simulations. For each catalog we model the HI distribution by using a simple
prescription to associate the HI gas mass to N-body halos. We find that the DE
models leave a distinct signature on the HI spectra across a wide range of
scales, which correlates with differences in the halo mass function and the
onset of the non-linear regime of clustering. In the case of the non-standard
DM model significant differences of the HI spectra with respect to the LCDM
model only arise from the suppressed abundance of low mass halos. These
cosmological model dependent features also appear in the 21cm spectra. In
particular, we find that future SKA measurements can distinguish the imprints
of DE and DM models at high statistical significance.
