The gravitoelectromagnetic stress-energy tensor
  We study the pseudo-local gravitoelectromagnetic stress-energy tensor for an arbitrary gravitational field within the framework of general relativity. It is shown that there exists a current of gravitational energy around a rotating mass. This gravitational analog of the Poynting flux is evaluated for certain classes of observers in the Kerr field. 
B. Mashhoon, J.C. McClune, and H. Quevedo