The World Lines of Isotropic Expansion in the De Sitter Universe


I. Lukavčević




The well-known Lemaitre coordinate transformation in de Sitter's spacetime, leading to an expanding Euclidean spatial metric, is obtained here as a particular case in a family of transformations. These transformations lead to non-geodesic radial world lines (except ,in the Lemaitre case) of isotropic expansion, with determined consequences for the metric and the acceleration of particles on them.