General Relativity and Flat Space. I
Abstract
Within the framework of the general theory of relativity, it is proposed to introduce at each point of spacetime a Euclidean metric tensor γ_{μν} in addition to the usual Riemannian metric tensor g_{μν}. In this way one imparts tensor character to quantities which in the usual form of the theory do not have it. For example, one can obtain a gravitational energymomentum density tensor in place of the usual pseudotensor. Furthermore one can impose four additional covariant conditions on the gravitational field and thus restrict the form of the solution for the field corresponding to a given physical situation.
 Publication:

Physical Review
 Pub Date:
 January 1940
 DOI:
 10.1103/PhysRev.57.147
 Bibcode:
 1940PhRv...57..147R