Non-Cold Dark Matter: Particle Physics versus Cosmology
Dark matter should represent 80% of the matter content of the Universe, yet its fundamental nature is still unknown. Even though the LambdaCDM model, with CDM for Cold dark matter, provides a very good fit to cosmological data, non-cold dark matter is still perfectly allowed. From a particle physics point of view, a plethora of models can account for all the dark matter. Among the latter, dark matter coupled only gravitationally or very feebly to the Standard model, or coupling to light degrees of freedom, are typical examples of scenarios that affect structure formation in a way similar to thermal warm dark matter: they are referred to as non-cold dark matter scenarios. In my talk I’ll discuss the typical imprint of such particle physics scenarios on the matter power spectrum. I will highlight how Cosmology, including 21cm Cosmology, together with Particle Physics experiments might help to distinguish between the non-cold dark matter candidates.