Density perturbations arising from multiple field slow-roll inflation

Abstract

In this paper we analyze scalar gravitational perturbations on a Robertson-Walker background in the presence of multiple scalar fields that take values on a (geometrically non-trivial) field manifold during slow-roll inflation. For this purpose modified and generalized slow-roll functions are introduced and their properties examined. These functions make it possible to estimate to what extent the gravitational potential decouples from the scalar field perturbations. The correlation function of the gravitational potential is calculated in an arbitrary state. We argue that using the vacuum state seems a reasonable assumption for those perturbations that can be observed in the CMBR. Various aspects are illustrated by examples with multiple scalar fields that take values on flat and curved manifolds.

42 pages; some minor changes and additions

References in corpus (2)

• Adiabatic and entropy perturbations from inflation
• New Constraints on inflation from the Cosmic Microwave Background

Cited by in corpus (48)

• Features of heavy physics in the CMB power spectrum
• Perturbations in generalized multi-field inflation
• Mass hierarchies and non-decoupling in multi-scalar field dynamics
• On the importance of heavy fields during inflation
• Heavy fields, reduced speeds of sound and decoupling during inflation
• Inflation, Cosmic Perturbations and Non-Gaussianities
• Oscillations in the stochastic gravitational wave background from sharp features and particle production during inflation
• Strongly Coupled Perturbations in Two-Field Inflationary Models
• Constraints on modular inflation in supergravity and string theory
• Preheating after Multifield Inflation with Nonminimal Couplings, I: Covariant Formalism and Attractor Behavior
• Nonlinear perturbations of cosmological scalar fields
• Multifield Inflation after Planck: Isocurvature Modes from Nonminimal Couplings
• Bootstrapping Multi-Field Inflation: non-Gaussianities from light scalars revisited
• Primordial fluctuations and non-Gaussianities from multifield DBI Galileon inflation
• Scaling attractors in multi-field inflation
• Hypernatural inflation
• Nonlinear perturbations of cosmological scalar fields with non-standard kinetic terms
• MultiModeCode: An efficient numerical solver for multifield inflation
• Large power spectrum and primordial black holes in the effective theory of inflation
• AdS and stabilized extra dimensions in multidimensional gravitational models with nonlinear scalar curvature terms 1/R and R^4
• Frame Covariance in Quantum Gravity
• Attractors, Bifurcations and Curvature in Multi-field Inflation
• Universality and scaling in multi-field $\alpha$-attractor preheating
• Multifield inflation beyond $N_{\mathrm{field}}=2$: non-Gaussianities and single-field effective theory
• Enhanced Curvature Perturbation and Primordial Black Hole Formation in Two-stage Inflation with a break
• Converting entropy to curvature perturbations after a cosmic bounce
• Consistency relations for sharp features in the primordial spectra
• The Hubble Slow Roll Expansion for Multi Field Inflation
• Multifield Dynamics in Higgs-otic Inflation
• The Eisenhart Lift for Field Theories
• The Non-Minimal Ekpyrotic Trispectrum
• Preheating from target space curvature and unitarity violation: Analysis in field space
• Inflation in Multi-field Modified DBM Potentials
• The Strong Multifield Slowroll Condition and Spiral Inflation
• A Finite Measure for the Initial Conditions of Inflation
• Magnon Inflation: Slow Roll with Steep Potentials
• Non-Gaussian CMB and LSS statistics beyond polyspectra
• Dark Matter from Entropy Perturbations in Curved Field Space
• (Slow-)Twisting inflationary attractors
• Coupling structure of multi-field primordial perturbations
• On the constant roll complex scalar field inflationary models
• Non-Gaussianity in rapid-turn multi-field inflation
• Multiple Field Inflation and Signatures of Heavy Physics in the CMB
• Adiabatic and isocurvature perturbations in extended theories with kinetic couplings
• The two-field regime of natural inflation
• Covariant evolution of perturbations during reheating in two-field inflation
• Adiabatic and Isocurvature Perturbation Projections in Multi-Field Inflation
• Cosmological signatures of brane inflation