Primordial perturbations from multifield inflation with nonminimal couplings
- Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
Realistic models of particle physics include many scalar fields. These fields generically have nonminimal couplings to the Ricci curvature scalar, either as part of a generalized Einstein theory or as necessary counterterms for renormalization in curved background spacetimes. We develop a gauge-invariant formalism for calculating primordial perturbations in models with multiple nonminimally coupled fields. We work in the Jordan frame (in which the nonminimal couplings remain explicit) and identify two distinct sources of entropy perturbations for such models. One set of entropy perturbations arises from interactions among the multiple fields. The second set arises from the presence of nonminimal couplings. Neither of these varieties of entropy perturbations will necessarily be suppressed in the long-wavelength limit, and hence they can amplify the curvature perturbation {zeta}, even for modes that have crossed outside the Hubble radius. Models that overproduce long-wavelength entropy perturbations endanger the close fit between predicted inflationary spectra and empirical observations.
- OSTI ID:
- 21408090
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 81, Issue 12; Other Information: DOI: 10.1103/PhysRevD.81.124037; (c) 2010 The American Physical Society; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COUPLING
DISTURBANCES
ENTROPY
GAUGE INVARIANCE
HUBBLE EFFECT
INFLATIONARY UNIVERSE
INTERACTIONS
PERTURBATION THEORY
RENORMALIZATION
SCALAR FIELDS
SPACE-TIME
SPECTRA
WAVELENGTHS
COSMOLOGICAL MODELS
INVARIANCE PRINCIPLES
MATHEMATICAL MODELS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES