Tensor to scalar ratio and large scale power suppression from pre-slow roll initial conditions

Journal Article · Thu May 01 04:00:00 EDT 2014 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2014/05/029· OSTI ID:22373565

Lello, Louis; Boyanovsky, Daniel ^[1]

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1. Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara St, Pittsburgh, PA 15260 (United States)

We study the corrections to the power spectra of curvature and tensor perturbations and the tensor-to-scalar ratio r in single field slow roll inflation with standard kinetic term due to initial conditions imprinted by a ''fast-roll'' stage prior to slow roll. For a wide range of initial inflaton kinetic energy, this stage lasts only a few e-folds and merges smoothly with slow-roll thereby leading to non-Bunch-Davies initial conditions for modes that exit the Hubble radius during slow roll. We describe a program that yields the dynamics in the fast-roll stage while matching to the slow roll stage in a manner that is independent of the inflationary potentials. Corrections to the power spectra are encoded in a ''transfer function'' for initial conditions T{sub α}(k), P{sub α}(k) = P{sup BD}{sub α}(k)T{sub α}(k), implying a modification of the ''consistency condition'' for the tensor to scalar ratio at a pivot scale k{sub 0}: r(k{sub 0}) = −8n{sub T}(k{sub 0}) [T{sub T}(k{sub 0})/T{sub R}(k{sub 0})]. We obtain T{sub α}(k) to leading order in a Born approximation valid for modes of observational relevance today. A fit yields T{sub α}(k) = 1+A{sub α}k{sup −p}cos [2πωk/H{sub sr}+φ{sub α}], with 1.5∼

• OSTI ID: 22373565
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 05 Vol. 2014; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
79 ASTRONOMY AND ASTROPHYSICS
CORRECTIONS
COSMOLOGICAL INFLATION
KINETIC ENERGY
PERTURBATION THEORY
POTENTIAL ENERGY
SCALARS
TENSORS
TRANSFER FUNCTIONS