Kosmologische Beobachtungen und ihre Beziehungen zum Standard-Weltmodell

Homogeneous-isotropic relativistic models of the universe which are based on assumptions concerning the occurrence of a hot big bang are considered. The suppositions of the models are briefly examined, taking into account questions regarding their justification. The observational information available for an evaluation of the correctness of the models is discussed, giving attention to the Hubble constant, the age of the universe, the acceleration parameter, the spectral distribution and isotropy of the microwave radiation, and questions of cosmic He and D formation. A comparison of the existing models with each other and with the observational data shows the instability of the models. It is concluded that the observational information currently available is not yet sufficient to answer questions concerning the 'correct' model of the universe