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Big bang nucleosynthesis: The standard model and alternativesBig bang nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the big bang cosmological model. This paper reviews the standard homogeneous-isotropic calculation and shows how it fits the light element abundances ranging from He-4 at 24% by mass through H-2 and He-3 at parts in 10(exp 5) down to Li-7 at parts in 10(exp 10). Furthermore, the recent large electron positron (LEP) (and the stanford linear collider (SLC)) results on the number of neutrinos are discussed as a positive laboratory test of the standard scenario. Discussion is presented on the improved observational data as well as the improved neutron lifetime data. Alternate scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conlusions on the baryonic density relative to the critical density, omega(sub b) remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the conclusion that omega(sub b) approximately equals 0.06. This latter point is the driving force behind the need for non-baryonic dark matter (assuming omega(sub total) = 1) and the need for dark baryonic matter, since omega(sub visible) is less than omega(sub b).
Document ID
19950044203
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Schramm, David N.
(Univ. of Chicago, Chicago, IL US, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1991
Publication Information
Publication: Physica Scripta
ISSN: 0281-1847
Subject Category
Astrophysics
Accession Number
95A75802
Funding Number(s)
CONTRACT_GRANT: NSF AST-88-22595
CONTRACT_GRANT: NAGW-1321
CONTRACT_GRANT: NAGW-1340
Distribution Limits
Public
Copyright
Other

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