Observational Constraints on the Averaged Universe
arXiv:1111.2214 · doi:10.1103/PhysRevD.85.043506
Abstract
Averaging in general relativity is a complicated operation, due to the general covariance of the theory and the non-linearity of Einstein's equations. The latter of these ensures that smoothing spacetime over cosmological scales does not yield the same result as solving Einstein's equations with a smooth matter distribution, and that the smooth models we fit to observations need not be simply related to the actual geometry of spacetime. One specific consequence of this is a decoupling of the geometrical spatial curvature term in the metric from the dynamical spatial curvature in the Friedmann equation. Here we investigate the consequences of this decoupling by fitting to a combination of HST, CMB, SNIa and BAO data sets. We find that only the geometrical spatial curvature is tightly constrained, and that our ability to constrain dark energy dynamics will be severely impaired until we gain a thorough understanding of the averaging problem in cosmology.
6 pages, 4 figures
References in corpus (20)
- Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
- Cosmic clocks, cosmic variance and cosmic averages
- Does the growth of structure affect our dynamical models of the universe? The averaging, backreaction and fitting problems in cosmology
- Accelerated expansion from structure formation
- A new framework for analyzing the effects of small scale inhomogeneities in cosmology
- Living in a Void: Testing the Copernican Principle with Distant Supernovae
- Dipole of the luminosity distance: a direct measure of H(z)
- Looking the void in the eyes - the kSZ effect in LTB models
- Multiscale cosmology and structure-emerging Dark Energy: A plausibility analysis
- Scale dependence of cosmological backreaction
- The kSZ effect as a test of general radial inhomogeneity in LTB cosmology
- On the onset of cosmological backreaction
- The influence of structure formation on the cosmic expansion
- Gravitational energy as dark energy: Concordance of cosmological tests
- Cosmological Backreaction from Perturbations
- Averaging in Spherically Symmetric Cosmology
- Averaging Spherically Symmetric Spacetimes in General Relativity
- A Complete Cosmological Solution to the Averaged Einstein Field Equations as found in Macroscopic Gravity
- Is dark energy an effect of averaging?
- Backreaction of superhorizon perturbations in scalar field cosmologies
Cited by in corpus (17)
- Beyond CDM: Problems, solutions, and the road ahead
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- Ricci focusing, shearing, and the expansion rate in an almost homogeneous Universe
- Spatial curvature endgame: Reaching the limit of curvature determination
- Evidence for an environment-dependent shift in the baryon acoustic oscillation peak
- Inhomogeneous cosmology and backreaction: Current status and future prospects
- Violation of the FRW consistency condition as a signature of backreaction
- Back-Reaction in Relativistic Cosmology
- Dark-energy dependent test of general relativity at cosmological scales
- Averaged Lemaître-Tolman-Bondi dynamics
- The Scale of Homogeneity in the Universe
- Backreaction mechanism in multifluid and extended cosmologies
- Expansion and Growth of Structure Observables in a Macroscopic Gravity Averaged Universe
- Observational Cosmology in Macroscopic Gravity
- On the Effects of Non-metricity in an Averaged Universe
- An Almost-FLRW Universe as the Averaged Geometry in Macroscopic Gravity