Density fluctuations in extended inflation

Journal Article · Wed Jan 15 04:00:00 EST 1992 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.45.426· OSTI ID:5082671

Guth, A H ^[1]; Jain, B ^[2]

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1. Center for Theoretical Physics, Laboratory for Nuclear Science, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)
2. Center for Theoretical Physics, Laboratory for Nuclear Science, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

We estimate the density perturbation spectrum {delta}{rho}/{rho} in the extended inflationary model, in which the scalar curvature is coupled to a Brans-Dicke field. Through a conformal transformation and a redefinition of the Brans-Dicke field, the action of the theory is cast into a form with no coupling to the scalar curvature and a canonical kinetic term for the redefined field. Following Kolb, Salopek, and Turner, we calculate {delta}{rho}/{rho} using the transformed action and the standard recipe developed for conventional inflation. This recipe is expected to give a valid order-of-magnitude estimate, but a precise calculation would require a more careful treatment of several aspects of the problem. The spectrum behaves as a positive power of the wavelength, a feature that might be useful in building models to account for the observed large-scale structure of the universe. Our result for the overall amplitude of density perturbations differs slightly from that of the previous authors, and the reasons for these differences are discussed. We also point out that the conformal transformation method can be applied to a wider class of generalized gravity theories.

• DOE Contract Number: AC02-76ER03069
• OSTI ID: 5082671
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 45:2; ISSN 0556-2821; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

661310* -- Relativity & Gravitation-- (1992-)
662110 -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COSMOLOGICAL MODELS
COUPLING
DIFFERENTIAL EQUATIONS
EQUATIONS
EQUATIONS OF MOTION
GRAVITATION
HUBBLE EFFECT
INFLATIONARY UNIVERSE
MATHEMATICAL MODELS
PARTIAL DIFFERENTIAL EQUATIONS
PERTURBATION THEORY
PHASE TRANSFORMATIONS
SCALAR FIELDS
VACUUM STATES