Compromise of localized graviton with a small cosmological constant in Randall–Sundrum scenario

A new mechanism which leads to a linearized massless graviton localized on the brane is found in the AdS/CFT setting, i.e., in a single copy of AdS5 spacetime with a singular brane on the boundary, within the Randall–Sundrum brane-world scenario. With an help of a recent development in path-integral techniques, a one-parameter family of propagators for linearized gravity is obtained analytically, in which a parameter ξ reflects various kinds of boundary conditions that arise as a result of the half-line constraint. In the case of a Dirichlet boundary condition (ξ=0) the graviton localized on the brane can be massless via coupling constant renormalization. Our result supports a conjecture that the usual Randall–Sundrum scenario is a regularized version of a certain underlying theory.