Constraints on backreaction in dust universes

Abstract

We study backreaction in dust universes using exact equations which do not rely on perturbation theory, concentrating on theoretical and observational constraints. In particular, we discuss the recent suggestion (in hep-th/0503117) that superhorizon perturbations could explain present-day accelerated expansion as a useful example which can be ruled out. We note that a backreaction explanation of late-time acceleration will have to involve spatial curvature and subhorizon perturbations.

15 pages, 1 figure. v2: The numbers in observational constraints corrected (no qualitative change), added discussion and references. v3: More references, clearer presentation, a new section on theoretical bounds. Conclusions stronger. v4: Published version. No major changes

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• Adhesive Gravitational Clustering
• Primordial inflation explains why the universe is accelerating today
• Backreaction of linear perturbations and dark energy
• Back-Reaction of Cosmological Perturbations in the Infinite Wavelength Approximation
• The Cosmic Quartet - Cosmological Parameters of a Smoothed Inhomogeneous Spacetime
• Cosmological Interpretation from High Redshift Clusters Observed Within the XMM-Newton $\Omega$-Project

Cited by in corpus (1)

• The universe seen at different scales