Primordial nucleosynthesis in the Brans-Dicke theory with a variable cosmological term
Abstract
Primordial abundances of light elements are calculated in the framework of the Brans-Dicke universe modified with a variable cosmological term, which is a function of the scalar field φ. Constraints on the parameters which appear in the modified Brans-Dicke cosmology are derived from comparisons with the observed abundances. The abundances of 2H, 3He and 7Li yield the bounds on the present matter density, while the 4He abundance primarily restricts the rate of change in φ. From these considerations, a model that has negative φin the early universe and, therefore, that has increasing gravitational "constant" G with time during the era of nucleosynthesis is proposed to be reasonable.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1987
- Bibcode:
- 1987A&A...179...17A
- Keywords:
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- Abundance;
- Cosmology;
- Gravitational Constant;
- Light Elements;
- Nuclear Fusion;
- Astrophysics