Cosmology and large mass hierarchy in multiply warped braneworld   scenario
  Hubble expansion in warped braneworld model is addressed in presence of more than one warped extra dimensions. It is shown that while the expansion depends on all the moduli, an exponential nature of the expansion of the scale factor emerges as a generic feature which is independent of the number of extra dimensions. Expression for the effective brane cosmological constant in such model has been derived. It is shown that similar to the 5-dimensional Randall-Sundrum model a fine tuning between the bulk cosmological constant and brane tension is required to obtain the desired cosmological constant on the brane. The length of the extra dimensions are determined in such scenario. Finally introduing pressureless matter in the bulk an observationally consistent cosmology was obtained on the visible brane. 
Narayan Banerjee, Sayantani Lahiri and Soumitra SenGupta
hep-th gr-qc hep-ph