相关论文: Low reheating temperature and the visible sterile …

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…

It is commonly assumed that the cosmological and astrophysical bounds on the mixings of sterile with active neutrinos are much more stringent than those obtained from laboratory measurements. We point out that in scenarios with a very low…

The expansion history and thermal physical process that happened in the early Universe before big bang nucleosynthesis (BBN) remains relatively unconstrained by observations. Low reheating temperature universes with normalcy temperatures of…

A laboratory detection of a sterile neutrino could provide the first indication of the evolution of the Universe before Big-Bang Nucleosynthesis (BBN), an epoch yet untested. Such "visible" sterile neutrinos are observable in upcoming…

We investigate how sterile neutrinos with a range of masses influence cosmology in MeV-scale reheating temperature scenarios. By computing the production of sterile neutrinos through the combination of mixing and scattering in the early…

Although the MiniBooNE experiment has severely restricted the possible existence of light sterile neutrinos, a few anomalies persist in oscillation data, and the possibility of extra light species contributing as a subdominant hot (or warm)…

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…

Standard simple assumptions are usually made about the pre-Big Bang Nucleosynthesis epoch, from which we do not have observations. Modifying these assumptions, the predicted density of relic particles such as neutralinos and sterile…

By combining data from cosmic microwave background (CMB) experiments (including the recent WMAP third year results), large scale structure (LSS) and Lyman-alpha forest observations, we constrain the hypothesis of a fourth, sterile, massive…

We present a comprehensive analysis of the effects of models with very low reheating scenarios ($T_\text{RH} \sim \mathcal{O}(\text{MeV})$) on the cosmological observables and derive corresponding bounds on the reheating temperature. With…

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…

Light sterile neutrinos represent a well-motivated extension of the 3-neutrino paradigm. However, the impressive agreement between standard cosmology and data casts doubts on their existence. Here we present a class of scenarios that…

A number of experimental anomalies involving neutrinos hint towards the existence of at least an extra (a very light) sterile neutrino. However, such a species, appreciably mixing with the active neutrinos, is disfavored by different…

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…

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…

A sterile neutrino in addition to the three known neutrinos seems unavoidable if one wants a simultaneous understanding of the results of the LSND experiment indicating $\nu_{\mu}-\nu_e$ oscillation together with other evidences for…

We propose a new explanation of the intriguing LSND evidence for electron antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a coupling with a light scalar and light (mostly active) neutrinos. We perform a fit to…

The connection between cosmological observations and neutrino physics is discussed in detail. Neutrinos decouple from thermal contact in the early Universe at a temperature of order 1 MeV which coincides with the temperature where light…

Short-baseline neutrino anomalies suggest the existence of low-mass ( m \sim O(1)~eV) sterile neutrinos \nu_s. These would be efficiently produced in the early universe by oscillations with active neutrino species, leading to a thermal…

It has been suggested that a sterile neutrino \nu_s which mixes with standard neutrinos can form nonthermal ``cool'' Dark Matter if its mass and mixing angle fall in the ranges 0.1 keV \lsim m_s \lsim 10 keV and 10^{-10} \lsim \sin^2 \theta…