Five-Dimensional Moving Brane Solutions with Four-Dimensional Limiting   Behaviour
  Under certain conditions some solutions to five-dimensional heterotic M-theory can be accurately described by the four-dimensional action of the theory - they have a four-dimensional limit. We consider the connection between solutions of four and five-dimensional heterotic M-theory when moving five-branes are present in the bulk. We begin by describing how to raise the known four-dimensional moving brane solutions to obtain approximate solutions to the five-dimensional theory, presenting for the first time the metric template necessary for this procedure. We then present the first solutions to the five-dimensional theory containing moving five-branes. We can then discuss the connection between our new exact five-dimensional solution and the four-dimensional ones. It is shown that our new solution corresponds to a solution with a static brane in four-dimensions. In other words our new solution could not have been identified as containing a moving brane from a purely four-dimensional viewpoint. 
Ed Copeland, James Gray, Andre Lukas and David Skinner