A toy model for slowly growing wormholes as effective topology changes
  We present a toy model for growing wormholes as a model of effective low-energy topology changes. We study the propagation of quantum fields on a $1+1$ spacetime analogous to the trouser-leg topology change. A low-energy effective topology change is produced by a physical model which corresponds to a barrier smoothly changing the tunneling probability between two spatial regions. 
Samuel L. Braunstein (SEECS, University of Wales, Bangor, UK)