Gravitational Lorentz Violation and Superluminality via AdS/CFT Duality

Understand

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 non-local perturbation of a special kind to the Hamiltonian of a four-dimensional conformal field theory with a weakly-coupled AdS dual, such as maximally supersymmetric Yang-Mills theory.
• In particular, two issues are given careful treatment: (1) the UV-completeness of our deformed 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.