  Discussion of the differences between the trajectory representation of Floyd
and that of Bouda and Djama [Phys. Lett. A 285 (2001) 27, quant-ph/0103071]
renders insight: while Floyd's trajectories are related to group velocities,
Bouda and Djama's are not. Bouda and Djama's reasons for these differences are
also addressed.

Quantum Physics;High Energy Physics - Theory