On a nonsingular isotropic cosmological model.
Abstract
The ParkerFulling (1973) mechanism for avoiding the initial singularity in homogeneous and isotropic cosmological models for a matterfilled universe is considered. According to this mechanism, the probability of having a nonsingular solution, although finite, is exceedingly low for any plausible model parameters if a homogeneous massive scalar field makes the main contribution to the energy density of the matter filling the universe. It is shown that the probability of avoiding a singularity in a homogeneous and isotropic model with the parameters of the real universe is about 1 in 10 to the 42nd. The physical reality of the postulated scalar field is questioned, and it is concluded that there are still no grounds for expecting that the collapse of a homogeneous and isotropic model can be replaced by expansion before spacetime curvature attains the Planck value and quantum gravitational effects become important.
 Publication:

Pisma v Astronomicheskii Zhurnal
 Pub Date:
 April 1978
 Bibcode:
 1978PAZh....4..155S
 Keywords:

 Astronomical Models;
 Cosmology;
 Equations Of State;
 Singularity (Mathematics);
 Flux Density;
 Gravitational Collapse;
 Homogeneity;
 Isotropy;
 Mathematical Models;
 Quantum Mechanics;
 Relativity;
 Scalers;
 Spatial Distribution;
 Astrophysics;
 Cosmological Models