Slow-roll corrections to inflaton fluctuations on a brane

Abstract

Quantum fluctuations of an inflaton field, slow-rolling during inflation are coupled to metric fluctuations. In conventional four dimensional cosmology one can calculate the effect of scalar metric perturbations as slow-roll corrections to the evolution of a massless free field in de Sitter spacetime. This gives the well-known first-order corrections to the field perturbations after horizon-exit. If inflaton fluctuations on a four dimensional brane embedded in a five dimensional bulk spacetime are studied to first-order in slow-roll then we recover the usual conserved curvature perturbation on super-horizon scales. But on small scales, at high energies, we find that the coupling to the bulk metric perturbations cannot be neglected, leading to a modified amplitude of vacuum oscillations on small scales. This is a large effect which casts doubt on the reliability of the usual calculation of inflaton fluctuations on the brane neglecting their gravitational coupling.

arXiv comment18 pages, 4 figures

References in corpus (23)

• An Alternative to Compactification
• The Einstein Equations on the 3-Brane World
• Brane cosmological evolution in a bulk with cosmological constant
• Brane-world gravity
• A more accurate analytic calculation of the spectrum of cosmological perturbations produced during inflation
• Gravity in the Randall-Sundrum Brane World
• Chaotic inflation on the brane
• Bent Domain Walls as Braneworlds
• Brane World Cosmology - Gauge-Invariant Formalism for Perturbation
• Steep inflation: ending braneworld inflation by gravitational particle production
• Gauge-invariant gravitational perturbations of maximally symmetric spacetimes
• Large-scale cosmological perturbations on the brane
• On Brane World Cosmological Perturbations
• Constraints on braneworld inflation from CMB anisotropies
• Observational constraints on braneworld chaotic inflation
• Scalar perturbations from brane-world inflation
• Inflaton potential reconstruction in the braneworld scenario
• Inflationary slow-roll formalism and perturbations in the Randall-Sundrum Type II braneworld
• Consistency equations in Randall-Sundrum cosmology: a test for braneworld inflation
• Brane preheating
• Quantization of scalar perturbations in brane-world inflation
• Degeneracy of consistency equations in braneworld inflation
• The consistency relation in braneworld inflation

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• Coupled bulk and brane fields about a de Sitter brane
• Gravitational waves and cosmological braneworlds: a characteristic evolution scheme
• Mass spectrum of primordial black holes from inflationary perturbation in the Randall-Sundrum braneworld: a limit on blue spectra
• Scalar perturbations in braneworld cosmology
• Primordial perturbations from slow-roll inflation on a brane
• Numerical study of curvature perturbations in a brane-world inflation at high-energies
• Inflaton perturbations in brane-world cosmology with induced gravity
• Brane-world inflation: slow-roll corrections to the spectral index
• Scalar cosmological perturbations in the Gauss-Bonnet braneworld