Title: On the Possibility of Anisotropic Curvature in Cosmology
Abstract: Although homogeneity and isotropy are two principles usually held in high esteem by cosmologists, it is important to test both assumptions observationally. I will discuss a special class of spacetimes which although homogeneous and shear-free, possesses anisotropic spatial curvature. This leads to a preferred direction in the sky but at the same time keeps both the expansion and the CMB isotropic at the background level. A distortion of the luminosity distances is derived and used to test the model against the CMB and supernovae. It is shown that future surveys could detect a possible preferred direction by observing ~ 20/(Omegak0)2 supernovae over the whole sky.