Cosmology from the Dark Ages

Precision cosmology as we know it today is based on observations of both the early Universe (the Cosmic Microwave Background) and late times, when the Universe is ionised again (Large Scale Structure, Supernovae Type Ia, Weak Lensing, etc.). The epoch between the last scattering surface and the cosmic dawn is called the Dark Ages, since the Universe is neutral and the only light emitted is via the Hydrogen hyperfine transition (21 cm line emission). Observations of the 21 cm Intensity Mapping form the Dark Ages provide a direct window into the matter density fluctuations free of complications such as galaxy bias and most astrophysical processes. Moreover, as this emission is very sensitive to changes in the temperature of the gas or the ionised gas fraction, it is the perfect probe for processes which inject energy in the medium. In this talk, I will review the potential of 21 cm Intensity Mapping in cosmology and focus on two major problems in cosmology: the progenitors of the supermassive black holes that have been observed at redshift around 7-8 (are they primordial black holes?) and the nature of dark matter (does it decay or annihilate?) and forecast the constraints that can be set on these models.