Shortcuts in particle production in a toroidal compactified spacetime
  We investigate the particle production in a toroidal compactified spacetime due to the expansion of a Friedmann cosmological model in R3 x S1 outside a U(1) local cosmic string. The case of a Friedmann spacetime is also investigated when torsion is incorporated in the connection. We present a generalization to toroidal compactification of p extra dimensions, where the topology is given by R3 x T^p. Some implications are presented and discussed. Besides the dynamics of spacetime, we also investigate in details the physical consequences of the topological transformations. 
Julio M. Hoff da Silva and Roldao da Rocha