Slow-roll and rapid-roll conditions in the spacelike vector field scenario
Abstract
In this note we derive the slow-roll and rapid-roll conditions for the minimally and nonminimally coupled spacelike vector fields. The function f(B2) represents the nonminimal coupling effect between vector fields and gravity, the f=0 case is the minimal coupling case. For a clear comparison with the scalar field, we define a new function F=±B2/12+f(B2), where B2=AμAμ, Aμ is the “comoving” vector field. With reference to the slow-roll and rapid-roll conditions, we find the small-field model is more suitable than the large-field model in the minimally coupled vector field case. As a nonminimal coupling example, the F=0 case just has the same slow-roll conditions as the scalar fields.
- Publication:
-
Physical Review D
- Pub Date:
- August 2009
- DOI:
- 10.1103/PhysRevD.80.043519
- arXiv:
- arXiv:0903.3269
- Bibcode:
- 2009PhRvD..80d3519Z
- Keywords:
-
- 98.80.Cq;
- Particle-theory and field-theory models of the early Universe;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Theory
- E-Print:
- no figure