Gravitational Lorentz violation and superluminality via AdS/CFT duality

A weak quantum mechanical coupling is constructed permitting superluminal communication within a preferred region of a gravitating AdS(5) spacetime. This is achieved by adding a spatially nonlocal perturbation of a special kind to the Hamiltonian of a four-dimensional conformal field theory with a weakly coupled AdS(5) dual, such as maximally supersymmetric Yang-Mills theory. In particular, two issues are given careful treatment: (1) the UV-completeness of our deformed conformal field theory (CFT), guaranteeing the existence of a "deformed string theory" AdS dual and (2) the demonstration that superluminal effects can take place in AdS, both on its boundary as well as in the bulk. Exotic Lorentz-violating properties such as these may have implications for tests of general relativity, addressing the cosmological constant problem, or probing behind horizons. Our construction may give insight into the interpretation of wormhole solutions in Euclidean AdS gravity.