CHAPTER 14 - RELATIVISTIC COSMOLOGY

Abstract

Publisher Summary This chapter highlights the issue of systematic construction and properties of the model of relativistic cosmology, which was derived from the theory of relativity. The solutions of the Einstein equations, the so-called isotropic cosmological model are based on the assumption of homogeneity and isotropy of the distribution of matter in space. The scalar curvature properties of an isotropic space are determined by just one constant. Corresponding to this, there are altogether three different possible cases for the spatial metric: (1) the so-called space of constant positive curvature (corresponding to a positive value of λ ), (2) space of constant negative curvature (corresponding to values of λ <0), and (3) space with zero curvature (λ = 0). Of these, the last will be a flat, which is Euclidean, space. The solution corresponding to an isotropic space of negative curvature—open isotropic model—is obtained by a method completely analogous to the preceding. The isotropic solutions found exist only when the matter density is different from zero; for empty space, the Einstein equations have no such solutions. The conclusion that the bodies are running away with increasing a (t) can only be made if the energy of interaction of the matter is small compared to the kinetic energy of its motion in the recession; this condition is always satisfied for sufficiently distant galaxies. In the opposite case, the mutual separations of the bodies are determined mainly by their interactions.