Randall-Sundrum with AdS(7)
  In the same sense that AdS_5 warped geometries arise naturally from Type IIB string theory with stacks of D3 branes, AdS_7 warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS_7 to get AdS_5 X Sigma^2, where the metric for Sigma^2 inherits the same warp factor as appears in the AdS_5. We analyze the 5d spectrum in detail for the case of a bulk scalar or a graviton in AdS_5 X T^2, in a setup which mimics the first Randall-Sundrum model. The results display novel features which might be observed in experiments at the CERN Large Hadron Collider. 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 AdS_7 could be interpreted as direct evidence for M theory. 
Ruoyu Bao and Joseph Lykken