Cosmic Microwave Background, Accelerating Universe and Inhomogeneous Cosmology

Abstract

We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous equations lead to luminosity distance and Hubble constant formulas that depend on the location of the observer. For a general inhomogeneous solution, it is possible for the deceleration parameter to differ significantly from the FLRW result. The deceleration parameter $q_0$ can be interpreted as $q_0>0$ ($q_0=1/2$ for a flat matter dominated universe) in a FLRW universe and be $q_0<0$ as inferred from the inhomogeneous enhancement that is embedded in a FLRW universe. A spatial volume averaging of local regions in the backward light cone has to be performed for the inhomogeneous solution at late times to decide whether the decelerating parameter $q$ can be negative for a positive energy condition. The CMB temperature fluctuations across the sky can be unevenly distributed in the northern and southern hemispheres in the inhomogeneous matter dominated solution, in agreement with the analysis of the WMAP power spectrum data by several authors. The model can possibly explain the anomalous alignment of the quadrupole and octopole moments observed in the WMAP data.

20 pages, no figures, LaTex file. Equations and typos corrected and references added. Additional material and some conclusions changed. Final published version

References in corpus (28)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• The Cosmological Constant and Dark Energy
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• 4-Year COBE DMR Cosmic Microwave Background Observations: Maps and Basic Results
• Supernova Limits on the Cosmic Equation of State
• Asymmetries in the CMB anisotropy field
• A high resolution foreground cleaned CMB map from WMAP
• The significance of the largest scale CMB fluctuations in WMAP
• Is the low-l microwave background cosmic?
• Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background
• Suppressing the lower Multipoles in the CMB Anisotropies
• Constraining the Topology of the Universe
• A Local Void and the Accelerating Universe
• Non-Gaussian Signatures in the Temperature Fluctuation Observed by the Wilkinson Microwave Anisotropy Probe
• Effect of inhomogeneities on the expansion rate of the Universe
• Do SNe Ia Provide Direct Evidence for Past Deceleration of the Universe?
• The Virgo Alignment Puzzle in Propagation of Radiation on Cosmological Scales
• Analyses of Type Ia Supernova Data in Cosmological Models with a Local Void
• New non-Gaussian feature in COBE-DMR Four Year Maps
• The Luminosity Distance in Perturbed FLRW Spacetimes
• Cosmological Observations in a Local Void
• Backreaction in the Lemaitre-Tolman-Bondi model
• Constraining CMB-consistent primordial voids with cluster evolution
• Dipole anisotropies of IRAS galaxies and the contribution of a large-scale local void
• Luminous Matter Distribution, Bulk Flows and Baryon Contents in Cosmological Models with a Local Void

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• Accelerated expansion from structure formation
• The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies I
• CMB anisotropies seen by an off-center observer in a spherically symmetric inhomogeneous universe
• Inhomogeneity and the foundations of concordance cosmology
• Establishing homogeneity of the universe in the shadow of dark energy
• "Swiss-Cheese" Inhomogeneous Cosmology & the Dark Energy Problem
• Average observational quantities in the timescape cosmology
• CMB multipole measurements in the presence of foregrounds
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• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies: The Effect of a Cosmological Constant
• Mapping Luminosity-Redshift Relationship to LTB Cosmology
• Local Void vs Dark Energy: Confrontation with WMAP and Type Ia Supernovae
• Declining rotation curves of galaxies as a test of gravitational theory
• The Effect of Large-Scale Inhomogeneities on the Luminosity Distance
• Constraints on large scale inhomogeneities from WMAP-5 and SDSS: confrontation with recent observations
• Bare Action and Regularized Functional Integral of Asymptotically Safe Quantum Gravity
• Late-time Inhomogeneity and Acceleration Without Dark Energy
• Broken Isotropy from a Linear Modulation of the Primordial Perturbations
• Light Propagation and Large-Scale Inhomogeneities
• Eddington-Born-Infeld action for dark energy and dark matter
• 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
• CMB quadrupole suppression: I. Initial conditions of inflationary perturbations
• Reconciling the local void with the CMB
• Statistics of extreme objects in the Juropa Hubble Volume simulation
• Non-isotropy in the CMB power spectrum in single field inflation
• Peculiar motions, accelerated expansion and the cosmological axis
• Testing Isotropy of Cosmic Microwave Background Radiation
• Swiss Cheese and a Cheesy CMB
• Averaging in Spherically Symmetric Cosmology
• Microwave sky and the local Rees-Sciama effect
• Cosmological Acceleration and Gravitational Collapse
• Tension in the Void: Cosmic Rulers Strain Inhomogeneous Cosmologies
• Large scale structure simulations of inhomogeneous LTB void models
• Complete solutions to the metric of spherically collapsing dust in an expanding spacetime with a cosmological constant
• Signals of Statistical Anisotropy in WMAP Foreground-Cleaned Maps
• Explicit Cosmological Coarse Graining via Spatial Averaging
• Averaging Spherically Symmetric Spacetimes in General Relativity
• Anisotropic universe with anisotropic sources
• Testing the Cosmic Anisotropy with Supernovae Data: Hemisphere Comparison and Dipole Fitting
• Analytical Estimate of the Effect of Spherical Inhomogeneities on Luminosity Distance and Redshift
• Evidence of Quasi-linear Super-Structures in the Cosmic Microwave Background and Galaxy Distribution
• Thermodynamics of Lemaitre-Tolman-Bondi Model
• Can Cosmic Parallax Distinguish Between Anisotropic Cosmologies?
• Age Problem in Lemaitre-Tolman-Bondi Void Models
• Harmonic Inpainting of the Cosmic Microwave Background Sky: Formulation and Error Estimate
• Probing violation of the Copernican principle via the integrated Sachs-Wolfe effect
• Can Relic Superhorizon Inhomogeneities be Responsible for Large-Scale CMB Anomalies?
• Effect of Foregrounds on the CMBR Multipole Alignment
• An analytic approach to perturbations from an initially anisotropic universe
• Can the Copernican principle be tested by cosmic neutrino background?
• An Inhomogeneous Model Universe Behaving Homogeneously
• DESIgning concordant distances in the age of precision cosmology: the impact of density fluctuations
• Physical geometry of the quasispherical Szekeres models
• The motion of galaxy clusters in inhomogeneous cosmologies
• CMB sky for an off-center observer in a local void I: framework for forecasts
• Anisotropic power spectrum and the observed low-l power in PLANCK CMB data
• Cosmic Acceleration Driven by Mirage Inhomogeneities
• Reconstruction of Missing Data using Iterative Harmonic Expansion
• Thermodynamics of the inhomogeneous perfect fluid LTB model: Modified Bekenstein-Hawking system
• Voids as Alternatives to Dark Energy and the Propagation of Gamma Rays through the Universe