scholarly journals Neutrino oscillations and the early universe

Open Physics ◽  
2004 ◽  
Vol 2 (3) ◽  
Author(s):  
Daniela Kirilova
Keyword(s):  
Early Universe ◽  
Neutrino Oscillation ◽  
Neutrino Oscillations ◽  
Atmospheric Neutrino ◽  
Short Review ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Cosmological Constraints ◽  
Theoretical Status

AbstractThe observational and theoretical status of neutrino oscillations in connection with solar and atmospheric neutrino anomalies is presented briefly. The effect of neutrino oscillations on the evolution of the early Universe is discussed in detail. A short review is given of the standard Big Bang Nucleosynthesis (BBN) and the influence of resonant and non-resonant neutrino oscillations on active neutrinos and on primordial synthesis of He-4. BBN cosmological constraints on neutrino oscillation parameters are discussed.

BBN AND NEUTRINO OSCILLATIONS IN THE EARLY UNIVERSE: A BRIEF REVIEW

2005 ◽  
Vol 20 (11) ◽  
pp. 2431-2435
Author(s):  
F. L. VILLANTE
Keyword(s):  
Early Universe ◽  
Neutrino Oscillations ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Big Bang Nucleosynthesis

We briefly review the physics of Big Bang Nucleosynthesis (BBN). We present, moreover, some recent results on active-sterile neutrino oscillations in the early universe and on their effects on BBN.

scholarly journals THE νμ↔νs INTERPRETATION OF THE ATMOSPHERIC NEUTRINO DATA AND COSMOLOGICAL CONSTRAINTS

2000 ◽  
Vol 15 (15) ◽  
pp. 2289-2328 ◽  
Author(s):  
PASQUALE DI BARI ◽  
PAOLO LIPARI ◽  
MAURIZIO LUSIGNOLI
Keyword(s):  
Atmospheric Neutrino ◽  
Big Bang ◽  
Large Contribution ◽  
Atmospheric Neutrinos ◽  
Big Bang Nucleosynthesis ◽  
Potential Conflict ◽  
Lepton Asymmetry ◽  
Cosmological Constraints ◽  
Physical Insight ◽  
Boltzmann Method

The data on atmospheric neutrinos can be explained assuming the existence of oscillations between νμ's and a light sterile neutrino with mixing close to maximal, and δm2~3×10-3 eV 2. This interpretation of the data is in potential conflict with the successes of big bang nucleosynthesis (BBN), since oscillations can result in a too large contribution of the sterile state to the energy density of the universe at the epoch of nucleosynthesis. The possibility to evade these cosmological constraints has been recently the object of some controversy. In this work we rediscuss this problem and find that the inclusion of a small mixing of the sterile state with ντ can result in the generation of a large lepton asymmetry that strongly suppress the νμ↔νs oscillations eliminating the possible conflict with BBN bounds. In this scheme the mass of the tau neutrino must be larger than few eV's and is compatible with cosmological bounds. Our calculations are performed using a Pauli–Boltzmann method. In this approach it is also possible to develop analytic calculations that allow physical insight in the processes considered and give support to the numerical results.

scholarly journals Impact of neutrino properties and dark matter on the primordial Lithium production

2019 ◽  
Vol 28 (08) ◽  
pp. 1950065 ◽  
Author(s):  
Tahani R. Makki ◽  
Mounib F. El Eid ◽  
Grant J. Mathews
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Nuclear Physics ◽  
Big Bang ◽  
Light Elements ◽  
Big Bang Nucleosynthesis ◽  
Chemical Potentials ◽  
The Creation ◽  
The Universe

The light elements and their isotopes were produced during standard big bang nucleosynthesis (SBBN) during the first minutes after the creation of the universe. Comparing the calculated abundances of these light species with observed abundances, it appears that all species match very well except for lithium (7Li) which is overproduced by the SBBN. This discrepancy is rather challenging for several reasons to be considered on astrophysical and on nuclear physics ground, or by invoking nonstandard assumptions which are the focus of this paper. In particular, we consider a variation of the chemical potentials of the neutrinos and their temperature. In addition, we investigated the effect of dark matter on 7Li production. We argue that including nonstandard assumptions can lead to a significant reduction of the 7Li abundance compared to that of SBBN. This aspect of lithium production in the early universe may help to resolve the outstanding cosmological lithium problem.

scholarly journals THE INTERFACE OF COSMOLOGY WITH STRING AND M(ILLENNIUM) THEORY

2001 ◽  
Vol 16 (30) ◽  
pp. 4803-4843 ◽  
Author(s):  
DAMIEN A. EASSON
Keyword(s):  
Early Universe ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Short Review ◽  
Big Bang ◽  
Space Time ◽  
String Cosmology ◽  
Brane World ◽  
Recent Developments ◽  
M Theory

The purpose of this review is to discuss recent developments occurring at the interface of cosmology with string and M theory. We begin with a short review of 1980s string cosmology and the Brandenberger–Vafa mechanism for explaining space–time dimensionality. It is shown how this scenario has been modified to include the effects of p-brane gases in the early universe. We then introduce the Pre-Big-Bang scenario (PBB), Hořava–Witten heterotic M theory and the work of Lukas, Ovrut and Waldram, and end with a discussion of large extra dimensions, the Randall–Sundrum model and Brane World cosmologies.

scholarly journals Alternative Solutions to Big Bang Nucleosynthesis

2000 ◽  
Vol 198 ◽  
pp. 25-34 ◽  
Author(s):  
Hannu Kurki-Suonio
Keyword(s):  
Neutrino Physics ◽  
Early Universe ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Standard Picture ◽  
Alternative Solutions

Standard big bang nucleosynthesis (SBBN) has been remarkably successful, and it may well be the correct and sufficient account of what happened. However, interest in variations from the standard picture come from two sources: First, big bang nucleosynthesis can be used to constrain physics of the early universe. Second, there may be some discrepancy between predictions of SBBN and observations of abundances. Various alternatives to SBBN include inhomogeneous nucleosynthesis, nucleosynthesis with antimatter, and nonstandard neutrino physics.

scholarly journals NEUTRINO SPECTRUM DISTORTION DUE TO OSCILLATIONS AND ITS BBN EFFECT

2004 ◽  
Vol 13 (05) ◽  
pp. 831-841 ◽  
Author(s):  
DANIELA KIRILOVA
Keyword(s):  
Sterile Neutrino ◽  
Big Bang ◽  
Neutrino Energy ◽  
Electron Neutrino ◽  
Initial Population ◽  
Neutrino Mixing ◽  
Big Bang Nucleosynthesis ◽  
Cosmological Constraints ◽  
Neutrino Spectrum ◽  
Primordial Abundance

We study the distortion of electron neutrino energy spectrum due to oscillations with the sterile neutrino νe↔νs, for different initial populations of the sterile state δNs at the onset of oscillations. The influence of this spectrum distortion on Big Bang Nucleosynthesis is analyzed. Only the case of an initially empty sterile state was studied in previous publications. The primordial abundance of 4He is calculated for all possible δNs:0≤δNs≤1 in the model of oscillations, effective after electron neutrino decoupling, for which the spectrum distortion effects on the neutron–proton transitions are the strongest. It is found that the spectrum distortion effect may be dominant, not only in the case of small δNs, but also in the case of large initial population of νs. For example, in the resonant case it may play a considerable role even for very large δNs~0.8. Cosmological constraints on neutrino mixing for small δNs are discussed.

Sign in / Sign up

Export Citation Format

Share Document