A Domain Wall Solution by Perturbation of the Kasner Spacetime
  Plane symmetric perturbations are applied to an axially symmetric Kasner spacetime which leads to no momentum flow orthogonal to the planes of symmetry. This flow appears laminar and the structure can be interpreted as a domain wall. We further extend consideration to the class of Bianchi Type I spacetimes and obtain corresponding results. 
George Kotsopoulos and Charles C. Dyer
gr-qc astro-ph.CO