An Inhomogeneous Model Universe Behaving Homogeneously

Abstract

We present a new model universe based on the junction of FRW to flat Lemaitre-Tolman-Bondi (LTB) solutions of Einstein equations along our past light cone, bringing structures within the FRW models. The model is assumed globally to be homogeneous, i.e. the cosmological principle is valid. Local inhomogeneities within the past light cone are modeled as a flat LTB, whereas those outside the light cone are assumed to be smoothed out and represented by a FRW model. The model is singularity free, always FRW far from the observer along the past light cone, gives way to a different luminosity distance relation as for the CDM/FRW models, a negative deceleration parameter near the observer, and correct linear and non-linear density contrast. As a whole, the model behaves like a FRW model on the past light cone with a special behavior of the scale factor, Hubble and deceleration parameter, mimicking dark energy.

23 pages, 19 figures, published version in GRG

References in corpus (19)

• 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
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Statefinder -- a new geometrical diagnostic of dark energy
• Report of the Dark Energy Task Force
• Distances, ages, and epoch of formation of globular clusters
• Do we really see a cosmological constant in the supernovae data ?
• Mimicking Dark Energy with Lemaitre-Tolman-Bondi Models: Weak Central Singularities and Critical Points
• An alternative to the cosmological 'concordance model'
• Nonlinear Structure Formation and "Apparent" Acceleration: an Investigation
• Cosmic Microwave Background, Accelerating Universe and Inhomogeneous Cosmology
• Late-time Inhomogeneity and Acceleration Without Dark Energy
• Can superhorizon perturbations drive the acceleration of the Universe?
• On the geometry of impulsive gravitational waves
• The Accelerated Expansion of the Universe Challenged by an Effect of the Inhomogeneities. A Review
• Structured FRW universe leads to acceleration: a non-perturbative approach
• Matching LTB and FRW spacetimes through a null hypersurface
• Matters of Gravity, the newsletter of the Topical Group in Gravitation of the American Physical Society

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• Apparent and average acceleration of the Universe
• Is dark energy an effect of averaging?
• Lensing effects in inhomogeneous cosmological models
• A Scaling Relation in Inhomogeneous Cosmology with k-essence scalar fields
• Gravitational backreaction in cosmological spacetimes
• Modified Averaging Processes in Cosmology and the Structured FRW model