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.

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.

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.

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.

SIZE OF MULTIPLY-CONNECTED UNIVERSE AND COSMIC BACKGROUND RADIATION

1993 ◽  
Vol 08 (28) ◽  
pp. 2615-2621 ◽  
Author(s):  
LI-ZHI FANG
Keyword(s):  
Spherical Harmonic ◽  
Temperature Fluctuation ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Multiply Connected ◽  
Cosmic Background ◽  
Spatial Topology ◽  
Spatial Size ◽  
Topology Of The Universe ◽  
The Universe

A few years ago, we proposed that the spatial topology of the universe can be detected by cosmic background radiation (CBR), because the amplitudes of the spherical harmonic expansion of CBR anisotropy are sensitively dependent on the size of the universe. Recently, this method has been applied to study the size of a T3 universe by using the COBE-DMR data of CBR temperature fluctuation. The new result of the lower limit to the cosmologically spatial size is found to be larger than the old values by a factor of about 5. Therefore, the model of cubic T3 small universe can be ruled out. This paper is a summary of this progress. The significance and remained problems of the spatial topology of the universe have also been discussed.

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