Gravitational Waves in a Class of Bimetric, Poincaré-Relativistic Gravitation Theories

A. Nairz
Institut für Theoretische Physik der Universität Innsbruck,
A-6020 Innsbruck, Technikerstr. 25, Austria

Received July 22, 1997

Abstract. This article is concerned with a more detailed investigation of gravitational radiation and related issues in a class of bimetric theories of gravitation on Minkowski spacetime that has recently been proposed. The linearized field equations of the gravitational field coupled to a conserved non-gravitational energy-momentum tensor are solved, the properties of the solution studied, and questions like the uniqueness of the solution and the absence of gauge degrees of freedom re-discussed in greater detail. A unique conserved energy-momentum tensor associated with the gravitational field (quadratic in the field and its first derivatives) is given by direct construction. Finally, the results are applied first to the investigation of how much energy there is contained in the radiation field and second to the prediction about the rate of orbital inspiral of a binary star system, e.g., PSR 1913+16, due to the radiative losses of energy via gravitational waves; it turns out that in the latter case, as in linearized general relativity, one obtains the famous Einstein "quadrupole formula".

submitted for publication to Phys. Rev. D (1997).