Scalar-tensor theories of gravitation: Foundations and prospects

Abstract

A generalization of Einstein's theory is discussed in which the gravitation is described by a tensor and a scalar field. The theory is more consistent with Mach's principle and less reliant on absolute properties of space. The modification involves a violation of the "strong principle of equivalence" on which Einstein's theory is based. In the original version of this new theory, the "constant" of gravitation G is varying and particle masses are fixed. Later on another version of the theory was given in which G is truly a constant and the particle masses vary. The two versions are related by a conformal transformation. The physical and mathematical foundations of this theory have been discussed and the field equations have been derived. The astrophysical and cosmological consequences of the theory have been elaborately reviewed. © 1983 Plenum Publishing Corporation.