Gravitational theories with nonzero divergence of the energymomentum tensor
Abstract
Assuming that the divergence of the energymomentum tensor is nonzero leads to a class of theories with consistent field equations and gauge conditions as well as compatibility with the Newtonian limit of the conservation laws. Both the Einstein and the BransDicke theories are used as models, but the extension to other viable theories such as vectormetric and twometric theories is possible. One particularly interesting theory emerges that agrees with the ordinary BransDicke theory except for the postNewtonian parameter zeta_{2,} which predicts nonconservation of total momentum. Unfortunately, no accurate experimental limits for this parameter are known. It thus remains for future experiments in lunarlaser ranging to test this theory.
 Publication:

Physical Review D
 Pub Date:
 July 1975
 DOI:
 10.1103/PhysRevD.12.376
 Bibcode:
 1975PhRvD..12..376S
 Keywords:

 Einstein Equations;
 Energy Transfer;
 Gravitation Theory;
 Momentum Theory;
 Tensors;
 Field Theory (Physics);
 Gauge Invariance;
 Lunar Rangefinding;
 Metric Space;
 Newton Theory;
 Astrophysics