On the stability of a soft-wall model

Understand

We investigate the stability and fluctuations of a soft wall model that has an asymptotically AdS metric and a scalar field that has an asymptotically power-law dependence in the conformal coordinate.

• By imposing UV boundary conditions, the soft wall mass scale can be fixed to be near the TeV scale and causes the radion to no longer be massless.
• A hierarchy between the weak scale and the Planck scale can be generated for various particle spectrum behavior, although natural values only occur for a gravitational sector containing scalar fields that act like unparticles.
• In addition, if bulk Standard Model fields have nonstandard couplings to the gravitational sector, then a discrete particle spectrum can be realized in the nongravitational sector.