1. H. Thirring andJ. Lense:Phys. Zeits.,19, 156 (1918);R. P. Kerr:Phys. Rev. Lett.,11, 237 (1963).
2. R. Brehme andB. DeWitt:Ann. of Phys.,9, 220 (1960). An error in this paper was corrected byJ. M. Hobbs:Ann. of Phys.,47, 141 (1968).
3. Note thatj μ is treated as a vector density of weight one.
4. See,e.g.,A. Peres:Bull. Res. Counc. Isr.,7, 171 (1968).
5. From Brehme and deWitt’s work (loc. cit., eq. (5.16)) one can see that, up toO(hv), F μ ν contains noD-terms. However, it can be seen that the following procedure works in the presence ofD-terms as well. This means that one can extend the present calculation to any required order ofv in a straightforward manner.