A contextual analysis of the early work of Andrzej Trautman and Ivor Robinson on equations of motion and gravitational radiation

In the mid-1950s, Andrzej Trautman published a series of papers connected with his dissertation work written under Leopold Infeld. In these, he drew upon the slow motion approximation developed by Infeld, the general covariance-based strong conservation laws enunciated by Bergmann and Goldberg, the Riemann tensor attributes explored by Goldberg and related geodesic deviation exploited by Pirani, the permissible metric discontinuities identified by Lichnerowicz, O’Brien and Synge, and finally Petrov’s classification of vacuum spacetimes. With several significant additions he produced a comprehensive overview of the state of research in equations of motion and gravitational waves that was presented in a widely cited series of lectures at King’s College, London, in 1958. Fundamental new contributions were the formulation of boundary conditions representing outgoing gravitational radiation, the deduction of its Petrov type, a covariant expression for null wave fronts, and a derivation of the correct mass loss formula due to radiation emission. Ivor Robinson, who attended Trautman’s London lectures, had already in 1956 developed a bi-vector based technique that had resulted in his rediscovery of exact plane gravitational wave solutions of Einstein’s equations. He was the first to characterize shear-free null geodesic congruences. He and Trautman soon developed a long-term collaboration whose initial fruits were the Robinson–Trautman metric, examples of which were exact spherical gravitational waves.