Galaxy correlations and the BAO in a void universe: structure formation as a test of the Copernican Principle

Abstract

A suggested solution to the dark energy problem is the void model, where accelerated expansion is replaced by Hubble-scale inhomogeneity. In these models, density perturbations grow on a radially inhomogeneous background. This large scale inhomogeneity distorts the spherical Baryon Acoustic Oscillation feature into an ellipsoid which implies that the bump in the galaxy correlation function occurs at different scales in the radial and transverse correlation functions. We compute these for the first time, under the approximation that curvature gradients do not couple the scalar modes to vector and tensor modes. The radial and transverse correlation functions are very different from those of the concordance model, even when the models have the same average BAO scale. This implies that if void models are fine-tuned to satisfy average BAO data, there is enough extra information in the correlation functions to distinguish a void model from the concordance model. We expect these new features to remain when the full perturbation equations are solved, which means that the radial and transverse galaxy correlation functions can be used as a powerful test of the Copernican Principle.

12 pages, 8 figures, matches published version

References in corpus (33)

• Detection of the Baryon Acoustic Peak in the Large-Scale Correlation Function of SDSS Luminous Red Galaxies
• Modified Gravity and Cosmology
• Baryonic Features in the Matter Transfer Function
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• The WiggleZ Dark Energy Survey: mapping the distance-redshift relation with baryon acoustic oscillations
• Clustering of Luminous Red Galaxies IV: Baryon Acoustic Peak in the Line-of-Sight Direction and a Direct Measurement of H(z)
• What galaxy surveys really measure
• A general test of the Copernican Principle
• Confronting Lemaitre-Tolman-Bondi models with Observational Cosmology
• Does the growth of structure affect our dynamical models of the universe? The averaging, backreaction and fitting problems in cosmology
• Large-Scale Anisotropic Correlation Function of SDSS Luminous Red Galaxies
• A covariant approach for perturbations of rotationally symmetric spacetimes
• Inhomogeneity and the foundations of concordance cosmology
• Establishing homogeneity of the universe in the shadow of dark energy
• Constraining Anisotropic Baryon Oscillations
• Observational constraints on inhomogeneous cosmological models without dark energy
• Beyond the plane-parallel and Newtonian approach: Wide-angle redshift distortions and convergence in general relativity
• Can we avoid dark energy?
• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Precision cosmology defeats void models for acceleration
• Scalar Perturbations on Lemaitre-Tolman-Bondi Spacetimes
• Perturbation Theory in Lemaitre-Tolman-Bondi Cosmology
• The radial BAO scale and Cosmic Shear, a new observable for Inhomogeneous Cosmologies
• The Cosmic Microwave Background in an Inhomogeneous Universe - why void models of dark energy are only weakly constrained by the CMB
• Reconciling the local void with the CMB
• How close can an Inhomogeneous Universe mimic the Concordance Model?
• Tension in the Void: Cosmic Rulers Strain Inhomogeneous Cosmologies
• Large scale structure simulations of inhomogeneous LTB void models
• A new method for the Alcock-Paczynski test
• 3D Spherical Analysis of Baryon Acoustic Oscillations
• Rendering Dark Energy Void
• Evolution of density perturbations in large void universe

Cited by in corpus (18)

• Fundamental Physics with the Square Kilometre Array
• Is the Observable Universe Consistent with the Cosmological Principle?
• Testing the Cosmic Anisotropy with Supernovae Data: Hemisphere Comparison and Dipole Fitting
• Effects of Linear Redshift Space Distortions and Perturbation Theory on BAOs: A 3D Spherical Analysis
• Age Problem in Lemaitre-Tolman-Bondi Void Models
• Extracting the late-time kinetic Sunyaev-Zel'dovich effect
• A null test of the Cosmological Principle with BAO measurements
• Reconstruction of cosmological matter perturbations in Modified Gravity
• Evolution of linear perturbations in spherically symmetric dust spacetimes
• Smoothing expansion rate data to reconstruct cosmological matter perturbations
• Complementary consistency test of the Copernican principle via Noether's theorem and machine learning forecasts
• The Spectre of Underdetermination in Modern Cosmology
• Evolution of linear perturbations in Lemaître-Tolman-Bondi void models
• Reconstructing the Thermal Sunyaev-Zel'dovich Effect in 3D
• Two-point correlation function of density perturbations in a large void universe
• Comparison of two approximation schemes for solving perturbations in a LTB cosmological model
• Newtonian self-gravitating system in a relativistic huge void universe model
• Linear perturbations in spherically symmetric dust cosmologies including a cosmological constant