A Dark Energy Model in Kaluza-Klein Cosmology
  We study a dynamic $\Lambda$ model with varying gravitational constant $G$ under the Kaluza-Klein cosmology. Physical features and the limitations of the present model have been explored and discussed. Solutions are found mostly in accordance with the observed features of the accelerating universe. Interestingly, signature flipping of the deceleration parameter is noticed and the present age of the Universe is also attainable under certain stringent conditions. We find that the time variation of gravitational constant is not permitted without vintage $\Lambda$. 
Utpal Mukhopadhyay, Ipsita Chakraborty, Saibal Ray and A.A. Usmani
physics.gen-ph