A new way of calculating the effective potential for a light radion

In Randall-Sundrum scenarios, with the Goldberger-Wise stabilization mechanism, a light radion effective action is defined by integrating out all heavy degrees of freedom in the path integral formalism. Performing the necessary constrained minimization of the full 5D action by the Lagrange multipliers method, we arrive to a new, much more economical, way of calculating the radion effective potential for different choices of the radion interpolating fields. The dependence of the effective potential on the choice of the radion interpolating field is investigated. The calculated exact effective potential is used as a reference for judging about the quality of various approximate methods used in the literature.