Supersymmetry at Large Distance Scales

We propose that the UV/IR relation that underlies the AdS/CFT duality may provide a natural mechanism by which high energy supersymmetry can have large distance consequences. We motivate this idea via (a string realization of) the Randall-Sundrum scenario, in which the observable matter is localized on a matter brane separate from the Planck brane. As suggested via the holographic interpretation of this scenario, we argue that the local dynamics of the Planck brane - which determines the large scale 4-d geometry - is protected by the high energy supersymmetry of the dual 4-d theory. With this assumption, we show that the total vacuum energy naturally cancels in the effective 4-d Einstein equation. This cancellation is robust against changes in the low energy dynamics on the matter brane, which gets stabilized via the holographic RG without any additional fine-tuning.