Inflationary Perturbations in Anisotropic, Shear-Free Universes

Abstract

In this work, the linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free spacetimes is developed. After constructing an explicit set of complete eigenfunctions in terms of which perturbations can be expanded, we identify the effective degrees of freedom during a generic slow-roll inflationary phase. These correspond to the anisotropic equivalent of the standard Mukhanov-Sasaki variables. The associated equations of motion present a remarkable resemblance to those found in perturbed Friedmann-Robertson-Walker spacetimes with curvature, apart from the spectrum of the Laplacian, which exhibits the characteristic frequencies of the underlying geometry. In particular, it is found that the perturbations cannot develop arbitrarily large super-Hubble modes.

arXiv comment24 pages, 2 figures

References in corpus (15)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• A general test of the Copernican Principle
• Large-angle anomalies in the CMB
• Theory of cosmological perturbations in an anisotropic universe
• Time drift of cosmological redshifts as a test of the Copernican principle
• Predictions from an anisotropic inflationary era
• Does the Isotropy of the CMB Imply a Homogeneous Universe? Some Generalised EGS Theorems
• On the Possibility of Anisotropic Curvature in Cosmology
• The Open Universe Grishchuk-Zel'dovich Effect
• Anisotropic cosmologies containing isotropic background radiation
• Inflationary Perturbations in Anisotropic, Shear-Free Universes
• An anisotropic cosmological model with isotropic background radiation
• Cosmological Perturbation Theory With Background Anisotropic Curvature

Cited by in corpus (16)

• Isotropization of the universe during inflation
• Hamiltonian theory of classical and quantum gauge invariant perturbations in Bianchi I spacetimes
• Inflationary Perturbations in Anisotropic, Shear-Free Universes
• Uniqueness of the Fock quantization of scalar fields in a Bianchi I cosmology with unitary dynamics
• Cosmological Signatures of Anisotropic Spatial Curvature
• SNe Ia Tests of Quintessence Tracker Cosmology in an Anisotropic Background
• Two-point Correlation Functions in Inhomogeneous and Anisotropic Cosmologies
• Tensor Perturbations in Anisotropically Curved Cosmologies
• Extended FLRW Models: dynamical cancellation of cosmological anisotropies
• Balancing Anisotropic Curvature with Gauge Fields in a Class of Shear-Free Cosmological Models
• Correlations across horizons in quantum cosmology
• Bianchi models with a free massless scalar field: invariant sets and higher symmetries
• Distance-Redshift Relations in an Anisotropic Cosmological Model
• Extending the LCDM model through shear-free anisotropies
• Can cosmic rotation resolve the Hubble tension? Constraints from CMB and large-scale structure
• Bianchi cosmologies in a Thurston-based theory of gravity