Date:
27. January 2017 - 11:30
Speaker:
Vivian Poulin (LAPTh)
Although the existence of Dark Matter (DM) is by now well-established thanks to a variety of observations on many different scales, its nature is still unknown and so are many of its most basics properties, such as its lifetime. Numerous relics from the early universe have been proposed in many extensions of the standard model of particle physics, in some cases unstable to processes injecting electromagnetic (e.m.) forms of energy (e.g. ‘superWIMP’, R-parity breaking SUSY models, Sterile neutrinos, Primordial black holes …), but also non-e.m. ones (e.g. the Majoron scenario or any kind of DM decaying into 'dark radiation’ that could be played by neutrinos).
In this talk, I would like to review how the study of CMB temperature and polarization anisotropies can be used to put stringeant constraints on the abundance of such electromagnetically *and non-electromagnetically* decaying exotic particles, as a function of their lifetime. I will then emphasize the synergy with CMB spectral distortions and Big Bang Nucleosynthesis studies when e.m. channels are switched on, and illustrate how the 21cm signal, one of the main target of future experiments, could be used in order to improve (but not always !) over these bounds.