Bimetric gravitation and cosmology
A previous analysis of the bimetric theory of gravitation employed the parametrized post-Newtonian (PPN) formalism and determined the PPN parameter on the basis of the assumed homogeneous and isotropic structure of the Universe. The present paper argues that the use of such cosmological considerations to evaluate a theory of gravitation is dangerous because many different cosmologies are possible if the Universe is assumed to be unique and governed by special laws of development. Some examples are given of the drastically different cosmologies that can be obtained with the bimetric theory, the PPN formalism, and the assumption that the Universe is unique and governed by special laws. It is concluded that there is apparently no valid argument at the present time for ruling out a bimetric theory of gravitation.