Cosmological Signatures of Anisotropic Spatial Curvature
  If one is willing to give up the cherished hypothesis of spatial isotropy,
many interesting cosmological models can be developed beyond the simple
anisotropically expanding scenarios. One interesting possibility is presented
by shear-free models in which the anisotropy emerges at the level of the
curvature of the homogeneous spatial sections, whereas the expansion is
dictated by a single scale factor. We show that such models represent viable
alternatives to describe the large-scale structure of the inflationary
universe, leading to a kinematically equivalent Sachs-Wolfe effect. Through the
definition of a complete set of spatial eigenfunctions we compute the two-point
correlation function of scalar perturbations in these models. In addition, we
show how such scenarios would modify the spectrum of the CMB assuming that the
observations take place in a small patch of a universe with anisotropic
curvature.
