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.

Cosmology: evidence for a ‘big bang’

1994 ◽  
Vol 2 (2) ◽  
pp. 155-164
Author(s):  
Martin J. Rees
Keyword(s):  
Present State ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Big Bang ◽  
Fundamental Physics ◽  
Cosmic Expansion ◽  
Cosmic Background ◽  
The Universe

During the last 25 years, evidence has accumulated that our universe has evolved, over a period of 10–15 billion years, from a hot dense fireball to its present state. Telescopes can detect objects so far away that the universe had only a tenth its present age when the light we now receive set out towards us. The cosmic background radiation, and the abundances of elements such as helium and lithium, permit quantitative inferences about what the universe was like when it had been expanding for only a few seconds. The laws of physics established in the laboratory apparently suffice for interpreting all astronomical phenomena back to that time. In the initial instants of cosmic expansion, however, the particle energies and densities were so extreme that terrestrial experiments offer no firm guidance. We will not understand why the universe contains the observed ‘mix’ of matter and radiation, nor why it is expanding in the observed fashion, without further progress in fundamental physics.

BLACK HOLE SINGULARITIES, CRITICAL PHENOMENA, THE RUNAWAY UNIVERSE AND HYPERSPACE TRAVEL

2003 ◽  
Vol 12 (09) ◽  
pp. 1675-1680
Author(s):  
LIOR M. BURKO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Energy ◽  
Radiation Field ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Radiation Fields ◽  
Cosmic Background ◽  
Expansion Of The Universe ◽  
The Universe

Black holes are always irradiated by the cosmic background radiation. This captured radiation field determines the physical and geometrical nature of the singularity inside the black hole. We find that non-compact radiation fields (similar to the cosmic background radiation) affect dramatically the singularity, and may determine the fate of a falling astronaut. In particular, the dark energy which accelerates the expansion of the universe determines whether the "tunnel" inside the black hole is blocked, or whether the possibility of using the black hole as a portal for hyperspace travel cannot be ruled out as yet.

scholarly journals PRIMORDIAL NUCLEOSYNTHESIS: SUCCESSES AND CHALLENGES

2006 ◽  
Vol 15 (01) ◽  
pp. 1-35 ◽  
Author(s):  
GARY STEIGMAN
Keyword(s):  
Particle Physics ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Big Bang ◽  
Primordial Nucleosynthesis ◽  
The Status ◽  
Independent Observations ◽  
Controlling Element ◽  
Standard Models ◽  
The Universe

Primordial nucleosynthesis provides a probe of the Universe during its early evolution. Given the progress exploring the constituents, structure, and recent evolution of the Universe, it is timely to review the status of Big Bang Nucleosynthesis (BBN) and to confront its predictions, and the constraints which emerge from them, with those derived from independent observations of the Universe at much later epochs in its evolution. Following an overview of the key physics controlling element synthesis in the early Universe, the predictions of the standard models of cosmology and particle physics (SBBN) are presented, along with those from some non-standard models. The observational data used to infer the primordial abundances are described, with an emphasis on the distinction between precision and accuracy. These relic abundances are compared with predictions, testing the internal consistency of BBN and enabling a comparison of the BBN constraints with those derived from the WMAP Cosmic Background Radiation data. Emerging from these comparisons is a successful standard model along with constraints on (or hints of) physics beyond the standard models of particle physics and of cosmology.

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.

scholarly journals Primordial nucleosynthesis: A cosmological probe

2009 ◽  
Vol 5 (S268) ◽  
pp. 19-26
Author(s):  
Gary Steigman
Keyword(s):  
Particle Physics ◽  
Background Radiation ◽  
Cosmological Parameters ◽  
Cosmic Background Radiation ◽  
Light Elements ◽  
Fundamental Physics ◽  
Primordial Nucleosynthesis ◽  
Cosmic Background ◽  
Standard Models ◽  
The Universe

AbstractDuring its early evolution the Universe provided a laboratory to probe fundamental physics at high energies. Relics from those early epochs, such as the light elements synthesized during primordial nucleosynthesis when the Universe was only a few minutes old, and the cosmic background photons, last scattered when the protons (and alphas) and electrons (re)combined some 400 thousand years later, may be used to probe the standard models of cosmology and of particle physics. The internal consistency of primordial nucleosynthesis is tested by comparing the predicted and observed abundances of the light elements, and the consistency of the standard models is explored by comparing the values of the cosmological parameters inferred from primordial nucleosynthesis with those determined by studying the cosmic background radiation.

On the cosmic background radiation and the age of the Universe

2013 ◽  
Vol 26 (3) ◽  
pp. 358-361
Author(s):  
Leandro Meléndez Lugo
Keyword(s):  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Big Bang ◽  
Microwave Background ◽  
Dispersion Process ◽  
Cosmic Background ◽  
Microwave Background Radiation ◽  
Age Of The Universe ◽  
The Big Bang ◽  
The Universe

A basic fundamental analysis indicates that any radiation emitted by remote objects, such as galaxies and quasars, has only a limited age in comparison with that of the Universe. The radiation emitted by such objects thousands of millions of years ago is the oldest one that can be detected. Any previous radiation emitted by these bodies during their dispersion process resulting from the Universe expansion cannot be detected. It is shown on the basis of this analysis that the age of the Universe is much greater than that established as 13,700 millions of years and that the cosmic microwave background radiation must have a source other than the Big Bang.

DENSITY FLUCTUATIONS ON SUPER-HUBBLE SCALES

1996 ◽  
Vol 11 (19) ◽  
pp. 1531-1538 ◽  
Author(s):  
LI-ZHI FANG ◽  
YI-PENG JING
Keyword(s):  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Density Fluctuations ◽  
Cosmic Background ◽  
Density Perturbations ◽  
Hubble Radius ◽  
The Universe

According to causality, the existence of density perturbations on scales larger than the present Hubble radius y = 2c/H0 is crucial to discriminate between inflation and non-inflation models of the origin of inhomogeneity of the universe. Observations of the cosmic background radiation anisotropies favor a super-Hubble suppression on scales λmax in the range 0.5–3.0y. Many of non-inflation models are consistent with such a suppression. Inflation models are certainly not in conflict with this suppression, however one important parameter, the duration of the epoch of inflation, may need to be fine tuned.

scholarly journals DIVISION VIII: GALAXIES AND THE UNIVERSE

2007 ◽  
Vol 3 (T26B) ◽  
pp. 179-180
Author(s):  
Francesco Bertola ◽  
Sadanori Okamura ◽  
Virginia L. Trimble ◽  
Mark Birkinshaw ◽  
Françoise Combes ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Large Scale ◽  
Local Group ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Cosmic Background ◽  
Distant Galaxies ◽  
The Universe

Division VIII gathers astronomers engaged in the study of the visible and invisible matter in the Universe at large, from Local Group galaxies via distant galaxies and galaxy clusters to the large-scale structure of the Universe and the cosmic background radiation.

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