Particle physics processes in cosmology through an effective Minkowski space formulation and the limitations of the method

TL;DR

This paper presents an effective Minkowski space approach for calculating particle physics processes in cosmology, simplifying computations by avoiding gravitational particle creation effects under certain conditions.

Contribution

It introduces a novel method to compute cosmological particle processes using flat space quantum field theory with specific applicability conditions.

Findings

The method effectively calculates decay rates and cross sections in cosmology.

It avoids gravitational particle creation effects in the calculations.

The approach is illustrated with a simple example.

Abstract

We introduce a method where particle physics processes in cosmology may be calculated by the usual perturbative flat space quantum field theory through an effective Minkowski space description at small time intervals provided that the running of the effective particle masses are sufficiently slow. We discuss the necessary conditions for the applicability of this method and illustrate the method through a simple example. This method has the advantage of avoiding the effects of gravitational particle creation in the calculation of rates and cross sections i.e. giving directly the rates and the cross sections due to the scatterings or the decay processes.