The Cosmological Problem as Initial Value Problem on the Observer's Past Light Cone: Observations

Abstract

AbstractIn a previous paper it was shown how cosmological models can be characterized by few initial data on the observer's past light cone. Part of the inner geometry of the past cone as well as some matter variables taken on the cone (in the simplest case the velocity and density of a cosmological fluid) determine a world model uniquely within the past light cone. Since the initial data to some degree enter the relations between observable quantities such as redshift, luminosity, angular diameter, number counts, distortion parameters and background radiation intensity, it might be possible to determine the required initial data from observations. This problem is discussed in the present article for some observable relatios involving the quantities just mentioned.