We analyze the structure of a recent nonlocal generalization of Einstein’s theory of gravitation by Mashhoon et al. By means of a covariant technique, we derive an expanded version of the nonlocality tensor which constitutes the theory. At the lowest orders of approximation, this leads to a simplification which sheds light on the fundamental structure of the theory and may prove useful in the search for exact solutions of nonlocal gravity.

• Received 10 March 2019

DOI:https://doi.org/10.1103/PhysRevD.99.104013