Cosmological models with pressure
Abstract
The effect of introducing on relativistic cosmological models is investigated. The investigation is carried out in the case where a polytropic relation between the pressure and the density exists, and in the special case where the pressure is proportional to the density. When pressure is introduced some of the models are reclassified. It is shown that the radial distance, and hence all the cosmological parameters that are functions of this distance are affected. As an example the apparent relation for a model with zero and nonzero pressure are shown. It is found that the introduction of pressure always tends to decrease the traveltime of light from an object and the age of a universe model.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 1968
 DOI:
 10.1093/mnras/138.3.313
 Bibcode:
 1968MNRAS.138..313S