Gravitational particle production by cosmic topological defects

Abstract

One of the consequences of the theory that describes the interaction of quantum fields with gravity is the creation of quantum particles by time depending gravitational fields. The creation of scalar and Dirac particles by small inhomogeneities in expanding cosmologies is discussed by using a perturbative approach based in the evaluation of the S-matrix. The results of that analysis are applied to the creation of particles by the topological defects that may have arisen in the early universe such as: domain walls, cosmic strings, global monopoles and cosmic textures.