Null Geodesics in Perturbed Spacetimes

Ted Pyne, Mark Birkinshaw
1993 Astrophysical Journal  
We present a generalization and refinement of the Sachs-Wolfe technique which unifies many of the approaches taken to date and clarifies both the physical and the mathematical character of the method. We illustrate the formalism with a calculation of the behavior of light passing a moving lens on a Minkowski background.
doi:10.1086/173178 fatcat:2f7gncpat5b2tpi23dnfge65pm