Anisotropic and Curved String Cosmologies

Abstract

Let us extend the work of the last Chapter to cosmologies containing spatial curvature terms [51]. This will enable us, via a qualitative analysis, to determine (among other things) whether models evolve from a low-curvature regime and thereby test the self-consistency of the low-energy effective string cosmology paradigm. In particular, we consider the class of “isotropic curvature” models [265, 314] , which are spatially homogeneous but contain non-trivial curvature and anisotropy and are characterized by the fact that the 3-dimensional Ricci curvature tensor is isotropic; i.e., ⁽³⁾ Rij is proportional to kδ _ij on the spatial hypersurfaces and these surfaces therefore have constant curvature k [265].