Related papers: Neutrino Oscillations in the Early Universe: A Rea…
We study the dynamics of active-sterile neutrino oscillations in the early universe using full momentum-dependent quantum-kinetic equations. These equations are too complicated to allow for an analytical treatment, and numerical solution is…
In the early universe, neutrinos decouple from equilibrium with the electromagnetic plasma at a temperature which is only slightly higher than the temperature where electrons and positrons annihilate. Therefore neutrinos to some extent…
We study the nonresonant oscillations between left-handed electron neutrinos nu_e and nonthermalized sterile neutrinos nu_s in the early Universe plasma. The case when nu_s do not thermalize till 2 MeV and the oscillations become effective…
Phenomenology of neutrino oscillations in vacuum and in cosmological plasma is considered. Neutrino oscillations in vacuum are usually described in plane wave approximation. In this formalism there is an ambiguity if one should assume…
Lepton asymmetry generated in the early universe by neutrino oscillations into sterile partners is calculated. Kinetic equations are analytically reduced to a simple form that permits an easy numerical treatment. Asymptotic values of the…
We studied nonequilibrium oscillations between left-handed electron neutrinos and nonthermalized sterile neutrinos. The exact kinetic equations for neutrinos, written in terms of neutrino density matrix in momentum space were analyzed. The…
The properties of the neutrino in the early universe have been investigated incorporating a small inhomogeneity in the mass density of the early universe. Dependence on this factor is found in studying mean free path and mass bound of…
The observational and theoretical status of neutrino oscillations in connection with solar and atmospheric neutrino anomalies is presented in brief. The effect of neutrino oscillations on the early Universe evolution is discussed in detail.…
We find the solution to the Dirac equation for a massive neutrino with a magnetic moment propagating in background matter and interacting with the twisting magnetic field. In frames of the relativistic quantum mechanics approach to the…
Recent work has shown that neutrino oscillations in matter can be greatly enhanced by flips between mass eigenstates if the medium is fluctuating with a period equal to the neutrino oscillation length. Here we investigate the effect of the…
As the increasing of neutrino energy or matter density, the neutrino oscillation in matter may undergo "vacuum-dominated", "resonance" and "matter-dominated" three different stages successively. Neutrinos endure very different matter…
We review the distortions of spectra of relic neutrinos due to the interactions with electrons, positrons, and neutrinos in the early universe. We solve integro-differential kinetic equations for the neutrino density matrix, including…
Particle oscillations following neutrino production processes are analysed within Feynman's path amplitude formulation of quantum mechanics. Consideration of the temporal sequence of production and detection events reveals an important…
In this lecture we review some of the basic properties of neutrinos, in particular their mass and the oscillation behavior. First we discuss how to describe the neutrino mass. Then, under the assumption that neutrinos are massive and mixed,…
We revisit the decoupling of neutrinos in the early universe with flavour oscillations. We rederive the quantum kinetic equations which determine the neutrino evolution based on a BBGKY-like hierarchy, and include for the first time the…
The Standard Model of particle physics describes neutrinos as massless, chargeless elementary particles that come in three different flavours. However, recent experiments indicate that neutrinos not only have mass, but also have multiple…
Neutrino mixing and basics of neutrino oscillations are considered. Recent evidences in favour of neutrino oscillations, obtained in the solar and atmospheric neutrino experiments, are discussed. Neutrino oscillations in the solar and…
Neutrino oscillations and mean-field effects considerably enrich the phenomenology of neutrino evolution in the early Universe. Taking into account these effects, most notably the neutrino self-interaction mean-field contribution, we…
Basics of neutrino oscillations is discussed. Importance of time-energy uncertainty relation is stressed. Neutrino oscillations in the leading approximation and evidence for neutrino oscillations are briefly summarized.
This review summarizes recent experimental and theoretical progress in determining neutrino mixing angles and masses through neutrino oscillations. We describe the basic physics of oscillation phenomena in vacuum and matter, as well as the…