Dynamical Stability of the AdS Soliton in Randall‐Sundrum Model

We study a generalization of the Randall‐Sundrum mechanism for generating the weak/Planck hierarchy, which uses two rather one warped extra dimension, and which requires no negative tension brane. The dynamical stability of the Radion mode will be studied. It is shown to have a tachyonic instability for certain models of the 4‐brane stress energy, while stable or massless in other models. If stable, its mass is in the milli‐eV range. The issue of the Radion stabilizationby a bulk scalar field is investigated.