G_2 Domain Walls in M-theory
  M-theory is considered in its low-energy limit on a G_2 manifold with non-vanishing flux. Using the Killing spinor equations for linear flux, an explicit set of first-order bosonic equations for supersymmetric solutions is found. These solutions describe a warped product of a domain wall in four-dimensional space-time and a deformed G_2 manifold. It is shown how these domain walls arise from the perspective of the associated four-dimensional N=1 effective supergravity theories. We also discuss the inclusion of membrane and M5-brane sources. 
Thomas House, Andre Lukas