The equivalence theorem and the production of gravitinos after inflation

We study the application of the high-energy equivalence between helicity $\pm 1/2$ gravitinos and goldstinos in order to calculate the production of helicity derive this equivalence for equations of motion, paying attention to several subtleties that appear in this context and are not present in the standard derivations of the theorem, mainly because of the presence of external sources. We also propose the Landau gauge as an alternative to the usual gauge choices given in the standard proofs at the Lagrangian level.