Self-Interactions in the Spacetime of a Scalar-Tensor Cosmic String
  We study the effect of the geometry and topology of a scalar-tensor cosmic string space-time on the electric and magnetic fields of line sources. It is shown that the dilatonic coupling of the gravity induces effects along the string comparable to a current flow allowing for forbidden regions near the string. 
I. V. L. Costa (IF/Unb), F. A. Oliveira (IF/Unb), M. E. X. Guimaraes   (MAT/Unb) and F. Moraes (DF/Ufpe and DF/Ufpb)