The forming of a physical boundary during the evolution of the Universe is the most important aspect of the whole process. Moreso than even the 3a_u criterion itself. This is because without a physical boundary the 3a_u criterion could not be established. The formation of a definable boundary in Phase I, will be due simply to the gradual depletion of available material in the greater Cosmos, from which the Universe could be formed.

A very important aspect in the formation of the Universe in Phase I is the time dilatation effect. This positive acceleration reaction of motion through the spatial gradient of its temporal rate, ensures that celestial masses arriving at the core do so slowly, avoiding violent collisions. This results in a distributed nature of masses throughout the Universe including the core.

The second most important aspect in the evolution process is the 3a_u criterion itself. Without this criterion the reversal of gravity would not occur. The 3a_u criterion is another facet of the internal gravitational field of every source. It only becomes physically significant however, firstly in sources as large as the Universe, where there is sufficient mass to create a gravitational radius that is of the same order of magnitude as the physical radius. Secondly, the only other stellar objects where this criterion is possible significant, is Neutron stars where, as shown in [3], the criterion is reached when, under gravitational compression after the fusion process at the core runs out of fuel, the physical radius of a large star collapses to less than three times its gravitational radius.

The third significant parameter in the evolution process, the boundary radius at the point of inflexion, was shown to be equal to the gravitational radius. Had the collapse continued below the gravitational radius, the direction of internal gravity would have again reversed, and the gravitational collapse continued to create a single stellar entity with the radial dimension of many light years. However, from Section 2.3, the analysis shows that at this critical point, the gravitational radius, where the inward motion of all stellar bodies is brought to a halt by the repulsive gravity field generated in Phase II, the magnitude of the field remains positive, thus ensuring that the subsequent expansion does indeed occur. Consequently, for the further collapse to the object described above, some extraneous influence that alters the process at the beginning of Phase II would have to be present. In view of the nature of Quasars, such a possibility cannot be entirely excluded.

Finally, the results of the development presented in this paper, together with those of [1], completes the overall characterisation of this new theory for the origin and existence of the Universe, as represented in the Relativistic Domain D₁. This new theory contains no anomalies of the type believed to exist in the "Big Bang", or modern Steady State models. This is largely due to an age of the Universe, as roughly estimated in [1], of some 45 billion years, and, in addition, the provision of a very good theoretical value of the Hubble "Constant", as also developed in [1].