On the stability of thick brane worlds non-minimally coupled to gravity

Understand

We analyze a class of 5D models where a 3 brane is generated by a bulk scalar field non minimally coupled to gravity.

• We show that perturbative stability of such branes is normally guaranteed although non minimal couplings are not innocuous in general.
• After the physical states are identified the linearized equations for propagating modes are evaluated into a Schroedinger form and supersymmetric quantum mechanics provides the absence of tachyons.
• The spectrum contains a tower of spin 2 and spin 0 fields with continuous masses starting from zero ones.