On the Possibility of Anisotropic Curvature in Cosmology
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 / (\Omega_{k0}^2) supernovae over the whole sky.
Cite
@article{arxiv.1006.3321,
title = {On the Possibility of Anisotropic Curvature in Cosmology},
author = {Tomi S. Koivisto and David F. Mota and Miguel Quartin and Tom G. Zlosnik},
journal= {arXiv preprint arXiv:1006.3321},
year = {2011}
}
Comments
Extended SNe analysis and corrected some CMB results. Text also extended and references added. 8 pages, 5 figures