Thick DGP braneworlds: Geometrical Origin of Inflation and of Present Acceleration of the Expansion

Dvali-Gabadadze-Porrati braneworlds with finite thickness are investigated. The physics of the model is governed by two length scales which are associated with the brane thickness and with the crossover length respectively. The immediate consequence is that, in a cosmological context, at early times, as well as at late times, gravity leaks into the extra dimension, while, at intermediate times, gravity is effectively 4D due to non-trivial physics occurring in standard DGP scenarios. This could be a nice scenario to address unified description of early inflation and late-time accelerated expansion of the universe.