Related papers: Effects of kination and scalar-tensor cosmologies …
We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can…
The hot and dense early Universe combined with the promise of high-precision cosmological observations provide an intriguing laboratory for Beyond Standard Model (BSM) physics. We simulate the early Universe to examine the effects of the…
The neutrino role in primordial nucleosynthesis is reviewed. The importance of nonequilibrium effects is emphasized both for the standard massless and possibly massive neutrinos. The upper bound on tau neutrino mass is presented. A spatial…
In light of the recent BICEP2 B-mode polarization detection, which implies a large inflationary tensor-to-scalar ratio r_{0.05}=0.2^{+0.07}_{-0.05}, we re-examine the evidence for an extra sterile massive neutrino, originally invoked to…
We re-examine neutrino oscillations in the early universe. Contrary to previous studies, we show that large neutrino asymmetries can arise due to oscillations between ordinary neutrinos and sterile neutrinos. This means that the Big Bang…
The role of the sterile neutrinos to the r-process nucleosynthesis in supernova explosions is studied. Previously it has been argued that a large part of neutrino mixing can be excluded if the supernovae are the origin of the heavy…
We consider relatively heavy neutrinos $\nu_H$, mostly contributing to a sterile state $\nu_s$, with mass in the range 10 MeV $\lesssim m_s \lesssim m_{\pi} \sim 135$ MeV, which are thermally produced in the early universe in collisional…
The sterile neutrino solutions to different irregular results and observations in neutrino physics are studied. It is pointed out that introducing sterile neutrinos helps to solve simultaneously the observed anomalies. It is argued that…
We outline how relic neutrino asymmetries may be generated in the early universe via active-sterile neutrino oscillations. We discuss possible consequences for big bang nucleosynthesis, within the context of a particular 4-neutrino model.
We summarize the impact of sterile neutrino dark matter on core-collapse supernova explosions. We explore various oscillations between electron neutrinos or mixed $\mu-\tau$ neutrinos and right-handed sterile neutrinos that may occur within…
We investigate the early Universe production of sterile neutrino Dark Matter by the decays of singlet scalars. All previous studies applied simplifying assumptions and/or studied the process only on the level of number densities, which…
I review the topic of relic neutrino asymmetry generation through active-sterile neutrino and antineutrino oscillations in the early universe. Applications to (i) the suppression of sterile neutrino production, and (ii) the primordial…
The standard cosmological model predicts the existence of a cosmic neutrino background with a present density of about 110 cm^{-3} per flavour, which affects big-bang nucleosynthesis, cosmic microwave background anisotropies, and the…
We point out that in scenarios with a low reheating temperature $T_R << 100$ MeV at the end of (the last episode of) inflation or entropy production, the abundance of sterile neutrinos becomes largely independent of their coupling to active…
The eV-scale sterile neutrino has been proposed to explain some anomalous results in experiments, \textit{such as} the deficit of reactor neutrino fluxes and the excess of $\bar{\nu}_\mu\to\bar{\nu}_e$ in LSND. This hypothesis can be tested…
We study a model of a keV-scale sterile neutrino with a relatively large mixing with the Standard Model sector. Usual considerations predict active generation of such particles in the early Universe, which leads to constraints from the…
We consider some consequences of the presence of a cosmological lepton asymmetry in the form of neutrinos. A relic neutrino degeneracy enhances the contribution of massive neutrinos to the present energy density of the Universe, and…
Light sterile neutrinos might mix with the active ones and be copiously produced in the early Universe. In the present paper, a detailed multi-flavor analysis of sterile neutrino production is performed. Making some justified approximations…
Sterile neutrinos with masses up to $\mathcal{O} (100)$ MeV can be copiously produced in a supernova (SN) core, through the mixing with active neutrinos. In this regard the SN 1987A detection of neutrino events has been used to put…
Unexplored interactions of neutrinos could be the key to understanding the nature of the dark matter (DM). In particular, active neutrinos with new self-interactions can produce keV-mass sterile neutrinos that account for the whole of the…