Randall-Sundrum membrane model with 7D anti-de Sitter space

In the same sense that AdS5 warped geometries arise naturally from Type IIB string theory with stacks of D3 branes, AdS7 warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS7 to get AdS5 x Σ2, where Σ2 is e.g. a torus T2 or a sphere S2. The metric for Σ inherits the same warp factor as appears in the AdS5. Bulk fields generically have both Kaluza-Klein and winding modes associated with Σ. In the effective 5d action these will contribute exotic new excitations. We analyze the 5d spectrum in detail for the case of a bulk scalar or a graviton in AdS5 x T2, in a setup which mimics the first Randall-Sundrum model. The results display several novel features, some of which might be observed in experiments at the LHC. For example, we obtain TeV scale string winding states without lowering the string scale. This is due to the double warping which is a generic feature of winding states along compactified AdS directions. Experimental verification of these signatures of AdS7 could be interpreted as direct evidence for M theory