Traversable intra-Universe wormholes and timeholes in General   Relativity: two new solutions
  Using thin shell formalism we construct two solutions of intra-universe wormholes. The first model is a cosmological analog of the Aichelburg-Schein timehole, while another one is an intra-universe form of the Bronnikov-Ellis solution. 
Alexey L. Smirnov
gr-qc