Shortcuts for graviton propagation in a six-dimensional brane world model

We consider a six-dimensional brane world model with asymmetric warp factors for time and both extra spatial coordinates, y and z. We derive the set of differential equations governing the shortest graviton path and numerically solve it for AdS-Schwarzschild and AdS-Reissner-Nordström bulks. In both cases we derive a set of conditions for the existence of shortcuts in bulks with shielded singularities and show some examples of shortcuts obtained under these conditions. Consequences are discussed.