  The radion in the Randall-Sundrum model is stabilized by the back reaction of
a bulk scalar field with its VEV depending on the fifth dimensional coordinate.
We studied the radion dynamics in an extended scenario, where intermediate
branes exist between the UV and IR branes. Our analysis proves that the
formalism of EFT delivers the same equations of motion as the linearized
Einstein equation with all junction conditions satisfied. The relic of 5d
diffeomorphism is broken after including the Goldberger-Wise stabilization and
a unique radion field is conjectured as legitimate in the RS metric
perturbation.
