相关论文: Sterile neutrino dark matter: A tale of weak inter…
Sterile neutrinos, fermions with no standard model couplings [SU(2) singlets], are predicted by most extensions of the standard model, and may be the dark matter. I describe the nonthermal production and linear perturbation evolution in the…
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 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…
The resonant production of keV sterile-neutrino dark matter mainly takes place during the QCD epoch of the early universe. It has been argued that it could be strongly affected by the opacities (or damping rates) of active neutrinos, which…
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…
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…
We study the production of sterile neutrinos in the early universe from $\pi \rightarrow l \nu_s$ shortly after the QCD phase transition in the absence of a lepton asymmetry while including finite temperature corrections to the $\pi$ mass…
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…
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…
It has been proposed that two resonances could coincide in the early universe at temperatures $T \sim 0.2 ... 0.5$ GeV: one between two nearly degenerate GeV-scale sterile neutrinos, producing a large lepton asymmetry through freeze-out and…
Sterile neutrinos with masses in the keV range are considered to be a viable candidate for warm dark matter. The rate of their production through active-sterile neutrino transitions peaks, however, at temperatures of the order of the QCD…
We determine the abundance of the lightest (dark matter) sterile neutrinos created in the Early Universe due to active-sterile neutrino transitions from the thermal plasma. Our starting point is the field-theoretic formula for the sterile…
The Universe may contain sufficiently small size matter-antimatter domains at temperatures of a few hundred MeV, without violating the success of Big Bang Nucleosynthesis. We demonstrate that this possibility enhances the keV scale sterile…
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 with a mass of a few keV can serve as cosmological warm dark matter. We study the production of keV sterile neutrinos in the early universe from the decay of a frozen-in scalar. Previous studies focused on heavy frozen-in…
We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range,…
Sterile neutrinos comprise an entire class of dark matter models that, depending on their production mechanism, can be hot, warm, or cold dark matter. We simulate the Local Group and representative volumes of the Universe in a variety of…
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…
Secret neutrino interactions can play an essential role in the origin of dark matter. We present an anatomy of production mechanisms for sterile neutrino dark matter, a keV-scale gauge-singlet fermion that mixes with active neutrinos, in…
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…