Homogeneous and isotropic cosmological models with ordinary matter and gravity predict slower expansion and shorter distances than observed. It is possible that this failure is due the known breakdown of homogeneity and isotropy related to structure formation, rather than new fundamental physics. We review this backreaction conjecture, concentrating on topics on which there has been progress as well as open issues.
Classical and Quantum Gravity
- Pub Date:
- August 2011
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- General Relativity and Quantum Cosmology
- 29 pages, 4 figures, contribution to Classical and Quantum Gravity special issue "Inhomogeneous Cosmological Models and Averaging in Cosmology". v2: Published version. Fixed typos, clarified text, added references