Studying Dark Matter properties with the CMB
In this talk, I would like to review how the CMB (in particular its temperature and polarization anisotropies) can be used to perform both direct and indirect detection of DM.
Firstly, I will show the great complementarity between underground direct detection experiment and the CMB in looking for direct scattering between dark and baryonic matter. I will then discuss how the CMB challenges the dark matter explanation of the EDGES anomaly — the observation of a puzzling absorption feature in the global 21cm signal. Secondly, I will show how the CMB can be used to put stringent constraints on DM models leading to energy injection, e.g DM annihilations, decay, PBH evaporation and accretion. I will compare CMB bounds to those coming from galactic cosmic and gamma ray searches and illustrate how the 21cm signal, a major target of next generation surveys, can be used to significantly improve over current limits.