Stability analysis of the Randall-Sundrum braneworld in presence of bulk scalar

The stability problem of Randall-Sundrum braneworld is readdressed in the light of stabilizing bulk scalar fields. It is shown that in such scenario the instability in general persists because of back-reaction even when an arbitrary potential is introduced for a canonical scalar field in the bulk. It is further shown that a bulk scalar field can indeed stabilize the braneworld when it has a tachyon-like action. The full back-reacted metric in such model is derived and a proper resolution of the hierarchy problem (for which the Randall-Sundrum scenario was originally proposed) is found to exist by suitable adjustments of the parameters of the scalar potential.