Propagation of cosmic rays in the foam-like Universe
  The model of a classical spacetime foam is considered, which consists of static wormholes embedded in Minkowski spacetime. We examine the propagation of particles in such a medium and demonstrate that a single thin ray undergoes a specific damping in the density of particles depending on the traversed path and the distribution of wormholes. The missing particles are scattered around the ray. Wormholes was shown to form DM halos around point-like sources. Therefore, the correlation predicted between the damping and the amount of DM can be used to verify the topological nature of Dark Matter. 
A.A. Kirillov, E.P. Savelova, P.S. Zolotarev