Total probability and number of fermion production in external electric field and magnetic field in de Sitter universe

摘要

In this paper we present a method for calculating the total probability corresponding to the processes of fermion pair production in dipole magnetic field and external Coulomb field in a de Sitter geometry. For that we rewrite the amplitudes in terms of oscillatory functions and we use the Taylor expansion of these functions for arriving at the final form of the momenta integrals. The total probability is analysed in terms of the ratio between the mass of the fermion and the Hubble parameter and we recover the Minkowski limit when the Hubble parameter is vanishing. Finally it is proven that from our results we can compute the number of fermions in terms of Hubble parameter.