The delta(0) Singularity in the Warped Mirabelli-Peskin Model
  The Mirabelli-Peskin model is a 5D super-Yang-Mills theory compactified on an orbifold $S^1/Z_2$ with the 4D Wess-Zumino model localized on the boundaries (or branes). As the 5D gauge multiplet couples to 4D chiral multiplets through delta functions, the model contains singular terms proportional to $\delta(0)$ after integrating out a 5D auxiliary field. This belongs to the same type of singularity as what was first noticed by Horava in the orbifold compactification of heterotic string theory. Mirabelli-Peskin showed that this singularity was field-theoretically harmless by demonstrating its neat cancellation by the singularity produced by the infinite sum of Kaluza-Klein (KK) excitation modes of bulk propagator. In this paper, the similar cancellation is proved to occur also in a warped version of Mirabelli-Peskin model with the background of ${AdS}_5$. The bulk propagator of scalar component of 5D vector supermultiplet in the warped extra dimension is explicitly KK expanded. Then, its second derivatives by the coordinates of $S^1/Z_2$ generate a term proportional to $\delta(0)$ at the boundaries. The cancellation is considered to take place perturbatively to all orders of coupling constants as well as to all loops. 
S.Ichinose and A.Murayama