Papers

Authors
Leo Brewin
Abstract
The detailed construction of six Regge spacetimes, each being an approximation to a time symmetric Friedmann dust filled universe, will be presented. These spacetimes are a generalization of those originally constructed by Collins and Williams\R(1). This paper will present new methods for the subdivision of each Cauchy surface into a set of tetrahedra, for the construction of the general 4-dimensional block and for the implementation of the constraints of homogeneity and isotropy. A new action sum for pure dust in a Regge spacetime will also be presented. The evolution of the Regge spaces will be seen to terminate prior to the full collapse of the universe. This will be shown to occur when the particle horizon for an observer at the centre of one tetrahedron has contracted so as to just touch the vertices of that tetrahedron. It is argued that this is a generic feature and will occur in any Regge spacetime whenever the local curvature becomes too large.