Dynamical mass and geodesic motion

We show that even though particles with dynamically generated masses do not have the standard point test particle energy-momentum tensor associated with them, their motion in an external gravitational field is nonetheless geodesic. We discuss dynamically massive conformal perfect fluids and construct conformal invariant particle trajectories for them, and show that such fluids behave just like standard kinematically massive perfect fluids in the particular conformal gauge in which the symmetry breaking field is taken to have a constant, spacetime independent vacuum expectation value.