The accelerating universe in brane-world cosmology
  The standard Friedmann universe embedded in a five dimensional and constant curvature bulk is examined without any a priori junction condition between the brane and the bulk. A geometrical explanation for the accelerated expansion of the universe is derived by using a minimum set of assumptions consistent with the brane-world program. It is shown that the extrinsic curvature of the brane can be associated to the dark energy which presumably drives the universe expansion. 
M.D. Maia, Edmundo M. Monte, J.M.F. Maia