Leptogenesis is one of the most appealing scenarios for the generation of the matter-antimatter asymmetry present in the Universe. It is usually computed considering a standard evolution of the early Universe as predicted by the LCDM cosmological model. Nevertheless, the properties of the Universe in epochs earlier than the Big-Bang Nucleosynthesis are not known. In fact, there could have existed an early black hole dominated era that ended when those primordial black holes (PBH) evaporated via Hawking radiation.
In this work, we have showed the impact of having an early black hole dominated Universe in standard leptogenesis. We have found that there is a non-trivial interplay between thermal and PBH-induced asymmetry. For instance, if PBHs evaporate before or at the same epoch of thermal leptogenesis, the effects are not significant. If the evaporation ocurrs after the thermal era, the PBHs can enhance or deplete the baryon asymmetry!
Since the dawn of the Universe, core collapse supernovae have been emitting a significant amount of neutrinos. These neutrinos, forming the so-called Diffuse Supernova Neutrino Background (DSNB) should be detectable in the next years. In this work, we have explored the different physics that can be learned after measuring the DSNB.
There are two basic categories for the exploitable physics, one related to slow neutrino properties, such as its lifetime or extremely large baseline oscillations, and another by measuring the astrophysical and cosmological effects that modify the propagation of neutrinos. We have explored these two types of scenarios, finding that next generation of experiments would be able to observe an expanding Universe using neutrinos.
Neutrino oscillations are a well-established phenomenon. Last results have achieved an important degree of precision in some oscillation parameters. However, there are still some unknowns, such as the mass ordering.
There are two possible ways in which neutrinos can be ordered, according to the electron neutrino content of the lightest mass eigenstate. In the normal ordering, the lightest neutrino has the largest nu_e content, while in the inverted scenario the lightest neutrino has the least content of electron flavor.
Latest results from T2K and NOvA results have a preference for the normal ordering. Nevertheless, and quite interestingly, when performing the combination of the data, we have showed that the inverted ordering is preferred instead.