Cosmological consequences of a rolling homogeneous scalar field
The cosmological consequences of a pervasive, rolling, self-interacting, homogeneous scalar field are investigated. A number of models in which the energy density of the scalar field red-shifts in a specific manner are studied. In these models the current epoch is chosen to be scalar-field dominated to agree with dynamical estimates of the density parameter, ..cap omega../sub dyn/approx.0.2, and zero spatial curvature. The required scalar-field potential is ''nonlinear'' and decreases in magnitude as the value of the scalar field increases. A special solution of the field equations which is an attractive, time-dependent, fixed point is presented. These models are consistent with the classical tests of gravitation theory. The Eoetvoes-Dicke measurements strongly constrain the coupling of the scalar field to light (nongravitational) fields. Nucleosynthesis proceeds as in the standard hot big-bang model. In linear perturbation theory the behavior of baryonic perturbations, in the baryon-dominated epoch, do not differ significantly from the canonical scenario, while the presence of a substantial amount of homogeneous scalar-field energy density at low red-shifts inhibits the growth of perturbations in the baryonic fluid. The energy density in the scalar field is not appreciably perturbed by nonrelativistic gravitational fields, either in the radiation-dominated, matter-dominated, or scalar-field-dominated epochs. On the basis of this effect, we argue that these models could reconcile the low dynamical estimates of the mean mass density with the negligibly small spatial curvature preferred by inflation.
- Research Organization:
- Joseph Henry Laboratories, Department of Physics, Princeton University, Princeton, New Jersey 08544
- OSTI ID:
- 6990461
- Journal Information:
- Phys. Rev. D; (United States), Vol. 37:12
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COSMOLOGICAL MODELS
SCALAR FIELDS
ENERGY DENSITY
FIELD EQUATIONS
GALAXIES
GENERAL RELATIVITY THEORY
GRAVITATIONAL FIELDS
HUBBLE EFFECT
NUCLEOSYNTHESIS
PERTURBATION THEORY
RED SHIFT
TIME DEPENDENCE
EQUATIONS
FIELD THEORIES
MATHEMATICAL MODELS
SYNTHESIS
640106* - Astrophysics & Cosmology- Cosmology
645400 - High Energy Physics- Field Theory
657003 - Theoretical & Mathematical Physics- Relativity & Gravitation