Neutrino physics with the cosmic microwave background radiation

The fluctuations in the Cosmic Microwave Background Radiation (CMBR) contain key information about the physical conditions in the early universe. Two new satellites are expected to measure the CMBR fluctuation spectrum so precisely that almost all the relevant cosmological parameters can be determined at the percent level. This is great news for particle physics since physics beyond the standard model is prone to manifest itself in the early universe and therefore make a detectable imprint on CMBR fluctuations. As an example of this, I discuss the prospects for measuring active-sterile neutrino oscillations and neutrino decays