Decay rates for first-order processes in de Sitter QED

In this paper, we study the problem of computing the total probabilities and transition rates for the processes that correspond to the first-order perturbation theory in de Sitter QED. Our results are obtained in the limit of large background expansion, when the Hubble constant is much larger than the particle masses, a limit which corresponds to the conditions of the early universe. We use dimensional regularization and minimal subtraction to renormalize the integrals which appear in our computations. Finally, we obtain finite results for the total probabilities and total rates corresponding to transitions which imply the generation of photons and electron–positron pairs from vacuum, or the emission of a photon by electrons or positrons.