On the Possibility of Anisotropic Curvature in Cosmology
arXiv:1006.3321 · doi:10.1103/PhysRevD.83.023509
Abstract
In addition to shear and vorticity a homogeneous background may also exhibit anisotropic curvature. Here a class of spacetimes is shown to exist where the anisotropy is solely of the latter type, and the shear-free condition is supported by a canonical, massless 2-form field. Such spacetimes possess a preferred direction in the sky and at the same time a CMB which is isotropic at the background level. A distortion of the luminosity distances is derived and used to test the model against the CMB and supernovae (using the Union catalog), and it is concluded that the latter exhibit a higher-than-expected dependence on angular position. It is shown that future surveys could detect a possible preferred direction by observing ~ 20 / (Ω_{k0}^2) supernovae over the whole sky.
Extended SNe analysis and corrected some CMB results. Text also extended and references added. 8 pages, 5 figures
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- Quantum backreaction in evolving FLRW spacetimes
- Inflationary Perturbations in Anisotropic, Shear-Free Universes
- Structure formation in an anisotropic universe: Eulerian perturbation theory
- Warm inflation with non-comoving scalar field and radiation fluid
- SNe Ia Tests of Quintessence Tracker Cosmology in an Anisotropic Background
- Tensor Perturbations in Anisotropically Curved Cosmologies
- Extended FLRW Models: dynamical cancellation of cosmological anisotropies
- Distance-Redshift Relations in an Anisotropic Cosmological Model
- Horndeski in motion
- Bianchi cosmologies in a Thurston-based theory of gravity