Power-law cosmological solution derived from DGP brane with a brane   tachyon field
  By studying a tachyon field on the DGP brane model, in order to embed the 4D standard Friedmann equation with a brane tachyon field in 5D bulk, the metric of the 5D spacetime is presented. Then, adopting the inverse square potential of tachyon field, we obtain an expanding universe with power-law on the brane and an exact 5D solution. 
Yongli Ping, Lixin Xu, Hongya Liu, Ying Shao