Collision of Domain Walls in asymptotically Anti de Sitter spacetime
  We study collision of two domain walls in 5-dimensional asymptotically Anti de Sitter spacetime. This may provide the reheating mechanism of an ekpyrotic (or cyclic) brane universe, in which two BPS branes collide and evolve into a hot big bang universe. We evaluate a change of scalar field making the domain wall and can investigate the effect of a negative cosmological term in the bulk to the collision process and the evolution of our universe. 
Yu-ichi Takamizu and Kei-ichi Maeda