gravrpp.dvi

Einstein's General Relativity, the current "standard" theory of gravitation, describes gravity as a universal deformation of the Minkowski metric: Alternatively, it can be defined as the unique, consistent, local theory of a massless spin-2 field h µν , whose source must then be the total, conserved energy-momentum tensor energy-momentum tensor of the Standard Model matter. The theory is invariant under arbitrary coordinate transformations: To solve the field equations Eq. (14.6) one needs to fix this coordinate gauge freedom. E.g. the "harmonic gauge" (which is the analogue of the Lorentz gauge, ∂ µ A µ = 0, in electromagnetism) corresponds to imposing the condition ∂ ν ( √ gg µν ) = 0