Plane Waves and Vacuum Interpolation
  A 1/2-BPS family of time dependent plane wave spacetimes which give rise to exactly solvable string backgrounds is presented. In particular a solution which interpolates between Minkowski spacetime and the maximally supersymmetric homogeneous plane wave along a timelike direction is analyzed. We work in d=4, N=2 supergravity, but the results can be easily extended to d=10,11. The conformal boundary of a particular class of solutions is studied. 
Guillermo A. Silva