The method of virtual quanta as a probe of the equivalence principle

We consider bremsstrahlung encounters between a test body of massm, chargee, and a large fixed massM with chargeQ. We use the method of virtual quanta, and calculate the total electromagnetic and gravitational energy radiated in such encounters. We consider both the case in which the deflection is principally electromagnetic in nature, and the case in which the deflection is principally gravitational. The results are interpreted by considering the predictions of the equivalence principle, for the behavior of the test particle,and for the behavior of the virtual quanta. As expected from the equivalence principle, the total radiation produced is larger for electromagnetic deflection than for a gravitational deflection through the same angle.Dedicated to the memory of Alfred Schild, born7 September 1921; died 24 May 1977. A good man, a great scholar, the best of friends.Research supported in part by NSF grant no. PHV76-07919 and by NATO Research grant no. 1002.