Summary formulas for these models of universe


From H O and given and density of radiation (of density today), one builds the metric for the isotropic universe, universe of radiation and matter (of density A today with . Let us put The metric is written:

where and with
Let us consider a light signal emitted at time te and receipt at time tr let us note respectively ze and zr and etc the redshifts, " rate of depreciation " of frequencies, etc associated by the formula at the times te and tr there is the following fundamental formula:

Let us put z the redshift of an observed object, we express according to z the moment date(z) after the beginning of the universe of the emission of the signal received today with a redshift of z, the following distances: temporal dt(z), luminosity dl(z) and angular da(z) of this object; the curvature radius R(z), the value of the Hubble parameter H(z), the densities of matter and radiation the deacceleration parameter q(z), the density parameter etc (we have the following EXACT FORMULAS)

To obtain the future behavior it is enough to replace 1+ z by (i.e. to vary z from 0 to -1).

The metric is written then by using z as temporal variable: