Infrared Behavior of Massive Scalar Matter Coupled to Gravity

Abstract

In the framework of causal perturbation theory we consider a massive scalar field coupled to gravity. In the field theoretic approach to quantum gravity we start with a massless second-rank tensor field. This tensor field is then quantized in a covariant way in Minkowski space. This article deals with the adiabatic limit for graviton radiative corrections in a scattering process of two massive scalar particles. We compute the differential cross section for Bremsstrahlung processes in which one of the outgoing particles emits a graviton of low energy, a so-called soft graviton. Since the emitted graviton will not be detected we must integrate over the energy of all soft gravitons. Furthermore we discuss the infrared behavior of graviton and matter self-energy contributions.