相关论文: Active-sterile neutrino oscillations in the early …

Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of…

In the framework of a 3+1 scheme with an additional inert state, we consider the thermalisation of sterile neutrinos in the early Universe taking into account the full $4\times4$ mixing matrix. The evolution of the neutrino energy…

Recent cosmological data favour additional relativistic degrees of freedom beyond the three active neutrinos and photons, often referred to as 'dark' radiation. Light sterile neutrinos is one of the prime candidates for such additional…

By numerically solving the appropriate Boltzmann equations, we study the production of sterile neutrinos in models with low reheating temperatures. We take into account the production in oscillations as well as in direct decays and compute…

Sterile neutrinos can be produced in the early universe via interactions with their active counterparts. For small active-sterile mixing angles, thermal equilibrium with the standard model plasma is not reached and sterile neutrinos are…

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…

Neutrino oscillations in the early Universe prior to the epoch of primordial nucleosynthesis is studied by implementing real time non-equilibrium field theory methods. We focus on two flavors of Dirac neutrinos, however, the formulation is…

We calculate the incoherent resonant and non-resonant scattering production of sterile neutrinos in the early universe. We find ranges of sterile neutrino masses, vacuum mixing angles, and initial lepton numbers which allow these species to…

An extensive, growing body of work has been penned on cosmologies that include one or more sterile neutrinos. Early entries in the literature formulated a Boltzmann-like equation describing sterile-neutrino production in a way that bypasses…

We derive the collision term relevant for neutrino quantum kinetic equations in the early universe and compact astrophysical objects, displaying its full matrix structure in both flavor and spin degrees of freedom. We include in our…

Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line…

We obtain non-linear kinetic equations for sterile neutrino occupancies and lepton minus baryon numbers by matching real time correlation functions of thermal fluctuations computed in an effective description to those computed in thermal…

Several long-standing anomalies from short-baseline neutrino oscillation experiments -- most recently corroborated by new data from MiniBooNE -- have led to the hypothesis that extra, 'sterile', neutrino species might exist. Models of this…

Ordinary-sterile neutrino oscillations can generate a significant lepton number asymmetry in the early Universe. We study this phenomenon in detail. We show that the dynamics of ordinary-sterile neutrino oscillations in the early Universe…

We investigate observable cosmological aspects of sterile neutrino dark matter produced via the freeze-in mechanism. The study is performed in a framework that admits many cosmologically interesting variations: high temperature production…

A phenomenological model with active and sterile neutrinos is used for calculations of neutrino oscillation characteristics at the normal mass hierarchy of active neutrinos. Taking into account the contributions of sterile neutrinos,…

We generalize gravitational particle production in a radiation-dominated $CPT$-symmetric universe to non-standard, but also $CPT$-symmetric early universe cosmologies. We calculate the mass of a right-handed "sterile" neutrino needed for it…

keV scale sterile neutrinos are excellent warm dark matter candidates. In the early Universe, these can be produced from oscillations and scatterings of active neutrinos. However, in the absence of any new physics, this mechanism is in…

Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via…

Sterile neutrinos are well-motivated and actively searched for new particles that would mix with the active neutrinos. We study their phenomenology when they are produced in the evaporation of early Universe black holes, a novel production…