RELATIVISTIC FIREWORKS - NOT A VIABLE MODEL FOR COSMOLOGY

The dynamics of the ''fireworks model'' for the universe is investigat ed, taking gravity fully into account. The fireworks model is a metaga lactic model, which means that all matter observed is assumed to be a part of the metagalaxy: a huge, but finite aggregate of matter. In thi s way, the need for an initial singularity is avoided, and the Hubble expansion may be a result from some sort of explosion. However, it has proved to be surprisingly difficult to explain the highest redshifts observed in this way. The fireworks model is a possible remedy to that problem, where high redshifts are obtained in successive steps of exp losion. In this paper, general relativistic Boltzmann-like equations a re derived to describe the dynamics of such a model. The model is appl ied to cosmology in two ways. First, the nonrelativistic limit without gravity is investigated. In this case there are exact solutions to th e equations. From these it is shown that a model with reasonable value s of the density parameter and the random component of the peculiar ve locity field cannot explain the highest redshifts observed. Then, a ge neral relativistic perfect fluid approximation is treated numerically. Solutions are obtained where the redshifts have acceptable values. Th e velocity dispersion, in agreement with the nonrelativistic result, i s by far too high to be compatible with observations.