Conformal Bulk Fields, Dark Energy and Brane Dynamics

In the Randall-Sundrum scenario we analyze the dynamics of a spherically symmetric 3-brane when the bulk is filled with matter fields. Considering a global conformal transformation whose factor is the $Z_2$ symmetric warp we find a new set of exact dynamical solutions for which gravity is bound to the brane. The set corresponds to a certain class of conformal bulk fields. We discuss the geometries which describe the dynamics on the brane of polytropic dark energy.