Related papers: Relic neutrino asymmetry evolution from first prin…
We perform a study of the flavour evolution in the early universe of a multi-flavour active-sterile neutrino system with parameters inspired by the short-baseline neutrino anomalies. In a neutrino-symmetric bath a "thermal" population of…
In the early universe, neutrinos are slightly coupled when electron-positron pairs annihilate transferring their entropy to photons. This process originates non-thermal distortions on the neutrino spectra which depend on neutrino flavour,…
The phenomena of neutrino oscillations emerges due to coherent superposition of different neutrino states. The entanglement of neutrinos with its environment can lead to a suppression of neutrino oscillations. The master equation for…
We consider some consequences of the presence of a cosmological lepton asymmetry in the form of neutrinos. Relic neutrino degeneracy enhances the contribution of massive neutrinos to the present energy density of the Universe, and modifies…
Sterile neutrinos are thermalised in the early Universe via oscillations with the active neutrinos for certain mixing parameters. The most detailed calculation of this thermalisation process involves the solution of the momentum-dependent…
We consider the neutrino physics of models with a sequentially broken U(2) flavor symmetry. Such theories yield the observed pattern of quark and lepton masses, while maintaining sufficient degeneracies between superparticles of the first…
In this dissertation, we study the evolution and properties of the relic (or cosmic) neutrino distribution from neutrino freeze-out at $T=O(1)$ MeV through the free-streaming era up to today, focusing on the deviation of the neutrino…
The conventional derivation of neutrino oscillation treats neutrino mass eigenstate as plane wave with an overall evolution phase. Nevertheless, due to the intrinsic parity-violating nature of weak interactions, only the left-chiral…
Neutrino asymmetry generation from active-sterile neutrino oscillations in the early Universe has different important cosmological effects. We discuss its basic features and present recent results on the borders of the generation for mixing…
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…
In the early Universe, or near a supernova core, neutrino flavor evolution may be affected by coherent neutrino-neutrino scattering. We develop a microscopic picture of this phenomenon. We show that coherent scattering does not lead to the…
We present an expression for the transition probability between Dirac or Majorana neutrino flavors obtained from first principles within quantum field theory. Our derivation is based on a standard quantum mechanical setup and includes the…
We present a formulation of the quantum kinetic equations (QKEs) which govern the evolution of neutrino flavor at high density and temperature. Here, the QKEs are derived from the ground up, using fundamental neutrino interactions and…
The article provides an overview of some advances in the mathematical understanding of the nature of the kinetic equations of quantum systems of many particles. The fundamental equations of modern mathematical physics are studied, in…
Many facets of nonclassicality are probed in neutrino system in the context of three flavour neutrino oscillations. The analysis is carried out for parameters relevant to two ongoing experiments NO$\nu$A and T2K, and also for the upcoming…
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…
A new theoretical framework, based on the quantum field theory of open systems applied to neutrinos, has been developed to describe the neutrino evolution in external environments accounting for the effect of the neutrino quantum…
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…
The matter-enhanced oscillations of two neutrino flavors are studied using a uniform semiclassical approximation. Unlike some analytic studies which have focused on certain exactly-solvable densities, this method can be used for an…
We examine medium-enhanced, neutrino scattering-induced decoherent production of dark matter candidate sterile neutrinos in the early universe. In cases with a significant net lepton number we find two resonances, where the effective…