Eternal acceleration from M-theory
  The dimensional reduction of $D$-dimensional spacetimes arising in string/M-theory, to the conformal Einstein frame, may give rise to cosmologies with accelerated expansion. Through a complete analysis of the dynamics of doubly warped product spacetimes, in terms of scale invariant variables, it is demonstrated that for $D \geq 10$, eternally accelerating 4-dimensional $\kappa = -1$ Friedmann cosmologies arise from dimensional reduction on an internal space with negative Einstein geometry. 
Lars Andersson, J. Mark Heinzle