The Effect of a Brans-Dicke Cosmology upon Stellar Evolution and the Evolution of Galaxies.
Abstract
The effect which a variable G cosmology, such as Brans-Dicke, will have on the evolution of individual stars and of galaxies composed of these stars was examined in the hope that present day observation of globular clusters or giant elliptical galaxies will provide a test for the Brans-Dicke theory. The higher value of the gravitational coupling coefficient G in the past history of various Brans-Dicke universes was studied in detail. A low density, open universe was selected for study: fractional closure density = 0.2, present Hubble constant = 55 km/s/Mpc, stellar formation at a redshift of 5, and the Brans-Dicke parameter omega = 6. In this universe a set of stellar evolutionary tracks was computed from the Zero-Age Main Sequence through the Giant Branch to the Horizontal Branch for approximately solar composition, (Y,Z) = (0.25, 0.02).
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1976
- Bibcode:
- 1976PhDT.........8P
- Keywords:
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- Physics: Astronomy and Astrophysics;
- Cosmology;
- Galactic Evolution;
- Hubble Diagram;
- Stellar Evolution;
- Elliptical Galaxies;
- Gravitational Constant;
- Red Shift;
- Star Clusters;
- Astrophysics