Chapter 2: The Tensor Modes in Flat Space–Time

Even if the evolution of gravitational waves in flat space–time has been qualitatively anticipated in the previous chapter, a more accurate treatment of the problem is a prerequisite for the subsequent developments. While in the first part of the chapter the linearization of general relativity around Minkowski space–time is specifically analyzed, in the second part the conventional discussion is complemented by a non-covariant approach where the supplementary polarizations of the gravitational waves are explicitly identified…