Higher dimensional cosmological model with a phantom field
  We consider a higher dimensional gravity theory with a negative kinetic energy scalar field and a cosmological constant. We find that the theory admits an exact cosmological solution for the scale factor of our universe. It has the feature that the universe undergoes a continuous transition from deceleration to acceleration at some finite time. This transition time can be interpreted as that of recent acceleration of our universe. 
S. T. Hong, J. Lee, T. H. Lee, and P. OH