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Title: Primordial perturbations from multifield inflation with nonminimal couplings

Abstract

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.

Authors:
;  [1]
  1. Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
Publication Date:
OSTI Identifier:
21408090
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 81; Journal Issue: 12; Other Information: DOI: 10.1103/PhysRevD.81.124037; (c) 2010 The American Physical Society; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 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

Citation Formats

Kaiser, David I, Todhunter, Audrey T, and Institut de Theorie des Phenomenes Physiques, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne. Primordial perturbations from multifield inflation with nonminimal couplings. United States: N. p., 2010. Web. doi:10.1103/PHYSREVD.81.124037.
Kaiser, David I, Todhunter, Audrey T, & Institut de Theorie des Phenomenes Physiques, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne. Primordial perturbations from multifield inflation with nonminimal couplings. United States. https://doi.org/10.1103/PHYSREVD.81.124037
Kaiser, David I, Todhunter, Audrey T, and Institut de Theorie des Phenomenes Physiques, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne. Tue . "Primordial perturbations from multifield inflation with nonminimal couplings". United States. https://doi.org/10.1103/PHYSREVD.81.124037.
@article{osti_21408090,
title = {Primordial perturbations from multifield inflation with nonminimal couplings},
author = {Kaiser, David I and Todhunter, Audrey T and Institut de Theorie des Phenomenes Physiques, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne},
abstractNote = {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.},
doi = {10.1103/PHYSREVD.81.124037},
url = {https://www.osti.gov/biblio/21408090}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 12,
volume = 81,
place = {United States},
year = {2010},
month = {6}
}