CP violating vacuum transition and Big Bang Nucleosynthesis

2005 ◽  
Vol 201 ◽  
pp. 451-452
Author(s):  
H. L. Duorah ◽  
R. K. Das
Keyword(s):  
Transition Temperature ◽  
Early Universe ◽  
Chemical Potential ◽  
Big Bang ◽  
Helium Abundance ◽  
Big Bang Nucleosynthesis ◽  
Primordial Nucleosynthesis ◽  
The Universe ◽  
Limiting Value ◽  
Made In

An analysis of primordial nucleosynthesis is made in the perspective of transition in the early universe from quark gluon to a hadronic phase in a CP violating vacuum. The universe opaque to color, quarks and anti quarks binds into globally colorless hadrons. u, d and s quarks are considered in a sea of degenerate neutrinos for the case of μve = μvμ = μvτ. The nn/np ratio is calculated for a transition temperature ˜ 100 − 200MeV for various values of neutrino degeneracy ξve = μve/T, μve being the chemical potential of electron type neutrino. The limiting value of ξve is found to be 2.38, if the upper bound of fractional helium abundance Yp is 0.26.

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 Big Bang Nucleosynthesis and Lepton Number Asymmetry in the Universe

1999 ◽  
Vol 183 ◽  
pp. 312-312
Author(s):  
K. Kohri ◽  
M. Kawasaki ◽  
Katsuhiko Sato
Keyword(s):  
Chemical Potential ◽  
High Redshift ◽  
Big Bang ◽  
Electron Neutrino ◽  
Light Elements ◽  
Big Bang Nucleosynthesis ◽  
Lepton Asymmetry ◽  
Stringent Constraint ◽  
Likelihood Analysis ◽  
The Universe

Recently it has been reported that there may be a discrepancy between big bang nucleosynthesis theory and observations (BBN crisis) (Hata et al., 1995). One way to solve the discrepancy might be to adopt some modifications of standard physics used in SBBN (Kawasaki et al, 1997). We show that BBN predictions agree with the primordial abundances of light elements, 4He, D, 3He and 7Li inferred from the observational data if the electron neutrino has a net chemical potential ξve due to lepton asymmetry (Kohri et al., 1997). We study BBN with the effects of the neutrino degeneracy in details using Monte Carlo simulation and make a likelihood analysis using the most recent data. We estimate that (95% C.L.) and (95% C.L.) adopting the presolar Deuterium abundance as the primordial values. If we adopted the low D abundance which is obtained by the observation of the high redshift QSO absorption systems, (95% C.L.) and The estimated chemical potential of ve is about 10−5 eV which is much smaller than experiments can detect (≃ 1 eV). In other words, BBN gives the most stringent constraint on the chemical potential of ve.

scholarly journals Primordial Nucleosynthesis with a background magnetic field

2020 ◽  
Vol 227 ◽  
pp. 02003
Author(s):  
Yudong Luo ◽  
Toshitaka Kajino ◽  
Motohiko Kusakabe ◽  
Michael A Famiano
Keyword(s):  
Magnetic Field ◽  
Early Universe ◽  
Big Bang ◽  
Detailed Calculation ◽  
Big Bang Nucleosynthesis ◽  
Capture Reaction ◽  
Primordial Nucleosynthesis ◽  
Electron Positron ◽  
Background Magnetic Field ◽  
The Magnetic Field

We present our recent detailed calculation of the impacts from a background magnetic field on Big Bang Nucleosynthesis (BBN). Namely, the magnetic field impacts on the electron-positron thermodynamics, time temper-ature relation and the screening potential of the early Universe. Most interest-ingly, we investigated the electron-positron relativistic screening potential with the background magnetic field, such potential might lead to a non trivial effect on the electron capture reaction which could finally affect the neutron to proton ratio.

scholarly journals The status of Big Bang nucleosynthesis in July 1988

1989 ◽  
Vol 8 ◽  
pp. 693-696
Author(s):  
Hubert Reeves
Keyword(s):  
Phase Transition ◽  
Big Bang ◽  
Theoretical Ground ◽  
Big Bang Nucleosynthesis ◽  
Primordial Nucleosynthesis ◽  
Hadron Phase ◽  
The Status ◽  
Primordial Abundance ◽  
Bona Fide ◽  
Made In

Important progresses have been made in two fronts in the few past years.On the theoretical ground, we have realized the importance of the quark-hadron phase transition as possibly influencing in a major way the yields of die primordial nucleosynthesis isotopes.On the observational ground, the status of lithium as a bona-fide cosmological observable has been confirmed and its primordial abundance can be evaluated with increased confidence.

scholarly journals Constraints on Dark Matter from Primordial Nucleosynthesis

1987 ◽  
Vol 117 ◽  
pp. 499-523
Author(s):  
Jean Audouze
Keyword(s):  
Dark Matter ◽  
Chemical Evolution ◽  
Big Bang ◽  
Baryon Density ◽  
Cosmological Parameter ◽  
Big Bang Nucleosynthesis ◽  
Primordial Nucleosynthesis ◽  
The Galaxy ◽  
Predicted Values ◽  
The Universe

Primordial nucleosynthesis which is responsible for the formation of the lightest elements (D, 3He, 4He and 7Li) provides a unique way to determine the present baryon density pB in the Universe and therefore the corresponding cosmological parameter ΩB. After a brief summary of the relevant abundance determinations and of the consequences of the Standard Big Bang nucleosynthesis, it is argued that one needs to call for specific models of chemical evolution of the Galaxy in order to reconcile the observations with the predictions of this model. In this context the predicted values for ΩB should range from 4 10−3 to 6 10−2. These values are significantly lower than those deduced from current M/L determinations.

Primordial Nucleosynthesis

1988 ◽  
Vol 20 (1) ◽  
pp. 658-660
Author(s):  
J. Audouze
Keyword(s):  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Big Bang ◽  
Cosmological Parameter ◽  
Big Bang Nucleosynthesis ◽  
Primordial Nucleosynthesis ◽  
Baryonic Density ◽  
Cosmic Background ◽  
Expansion Of The Universe ◽  
The Universe

Primordial nucleosynthesis which is responsible for the formation of the lightest elements (D, 3He, 4HE and 7Li) might be as important as the overall expansion of the Universe and the cosmic background radiation to prove the occurrence of a dense and hot phase for the Unvierse about 15 billion years ago. As recalled in many reviews (e.g. refs. 1, 2) the standard Big Bang nucleosynthesis leads to two important conclusions regarding (i) a limitation of the baryonic density such that the corresponding cosmological parameter ΩB ≤ 0.1; (ii) a limitation of the number of neutrino flavours to 3-4 consistent with the results concerning the widths of the Z0 and W± particles3.

scholarly journals Introduction to big bang nucleosynthesis and modern cosmology

2017 ◽  
Vol 26 (08) ◽  
pp. 1741001 ◽  
Author(s):  
Grant J. Mathews ◽  
Motohiko Kusakabe ◽  
Toshitaka Kajino
Keyword(s):  
Nuclear Reactions ◽  
Big Bang ◽  
Cosmological Models ◽  
Big Bang Nucleosynthesis ◽  
Primordial Nucleosynthesis ◽  
Current State ◽  
Modern Cosmology ◽  
Basic Equations ◽  
The Big Bang ◽  
The Universe

Primordial nucleosynthesis remains as one of the pillars of modern cosmology. It is the testing ground upon which many cosmological models must ultimately rest. It is our only probe of the universe during the important radiation-dominated epoch in the first few minutes of cosmic expansion. This paper reviews the basic equations of space-time, cosmology, and big bang nucleosynthesis. We also summarize the current state of observational constraints on primordial abundances along with the key nuclear reactions and their uncertainties. We summarize which nuclear measurements are most crucial during the big bang. We also review various cosmological models and their constraints. In particular, we analyze the constraints that big bang nucleosynthesis places upon the possible time variation of fundamental constants, along with constraints on the nature and origin of dark matter and dark energy, long-lived supersymmetric particles, gravity waves, and the primordial magnetic field.

scholarly journals Relativistic Cosmology with an Introduction to Inflation

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 276
Author(s):  
Muhammad Zahid Mughal ◽  
Iftikhar Ahmad ◽  
Juan Luis García Guirao
Keyword(s):  
Standard Model ◽  
Early Universe ◽  
Large Scale ◽  
Initial Conditions ◽  
Big Bang ◽  
Relativistic Cosmology ◽  
The Standard Model ◽  
Big Bang Model ◽  
The Big Bang ◽  
The Universe

In this review article, the study of the development of relativistic cosmology and the introduction of inflation in it as an exponentially expanding early phase of the universe is carried out. We study the properties of the standard cosmological model developed in the framework of relativistic cosmology and the geometric structure of spacetime connected coherently with it. The geometric properties of space and spacetime ingrained into the standard model of cosmology are investigated in addition. The big bang model of the beginning of the universe is based on the standard model which succumbed to failure in explaining the flatness and the large-scale homogeneity of the universe as demonstrated by observational evidence. These cosmological problems were resolved by introducing a brief acceleratedly expanding phase in the very early universe known as inflation. The cosmic inflation by setting the initial conditions of the standard big bang model resolves these problems of the theory. We discuss how the inflationary paradigm solves these problems by proposing the fast expansion period in the early universe. Further inflation and dark energy in fR modified gravity are also reviewed.

scholarly journals Dynamo effects in gravity

2019 ◽  
Vol 127 ◽  
pp. 02009
Author(s):  
Boris Shevtsov
Keyword(s):  
Gravitational Constant ◽  
Nonlinear Oscillations ◽  
Big Bang ◽  
Baryon Asymmetry ◽  
System Of Equations ◽  
Fractal Structures ◽  
Expansion Of The Universe ◽  
The Big Bang ◽  
The Universe ◽  
Made In

Nonlinear oscillations in the dynamic system of gravitational and material fields are considered. The problems of singularities and caustics in gravity, expansion and baryon asymmetry of the Universe, wave prohibition of collapse into black holes, and failure of the Big Bang concept are discussed. It is assumed that the effects of the expansion of the Universe are coupling with the reverse collapse of dark matter. This hypothesis is used to substantiate the vortex and fractal structures in the distribution of matter. A system of equations is proposed for describing turbulent and fluctuation processes in gravitational and material fields. Estimates of the di usion parameters of such a system are made in comparison with the gravitational constant.

scholarly journals Searching for space-time variation of the fine structure constant using QSO spectra: overview and future prospects

2009 ◽  
Vol 5 (H15) ◽  
pp. 304-304
Author(s):  
J. C. Berengut ◽  
V. A. Dzuba ◽  
V. V. Flambaum ◽  
J. A. King ◽  
M. G. Kozlov ◽  
...  
Keyword(s):  
Nuclear Reactor ◽  
Structure Constant ◽  
Big Bang ◽  
The Other ◽  
Fine Structure Constant ◽  
Spatial And Temporal Variation ◽  
Fundamental Constants ◽  
Future Prospects ◽  
Big Bang Nucleosynthesis ◽  
The Universe

Current theories that seek to unify gravity with the other fundamental interactions suggest that spatial and temporal variation of fundamental constants is a possibility, or even a necessity, in an expanding Universe. Several studies have tried to probe the values of constants at earlier stages in the evolution of the Universe, using tools such as big-bang nucleosynthesis, the Oklo natural nuclear reactor, quasar absorption spectra, and atomic clocks (see, e.g. Flambaum & Berengut (2009)).

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