Ponente
Descripción
Particle production from the vacuum is one of the most remarkable consequences of quantum field theory in the presence of non-dynamical backgrounds, with the Schwinger effect providing a paradigmatic example. In this work, we study particle-production processes in quantum field theories coupled to non-dynamical backgrounds within a functional formalism.
The external field is incorporated non-perturbatively into the free theory, modifying the corresponding free operator and its propagator. As a consequence, the natural basis is no longer given by plane waves, but by eigenfunctions of the background-dependent free operator. Interactions can then be introduced to study scattering and particle-production processes, which requires a suitable modification of the LSZ reduction formula.
We focus on a complex scalar field in the presence of a constant electric source, for which the modes can be expressed in terms of Weber functions. Within this framework, we investigate the production of two particle–antiparticle pairs from the vacuum, together with the related crossed processes, providing a setting in which to study how external backgrounds modify interaction amplitudes and particle production.
