Abstract:
In a recent paper (1912.05649), my collaborators and I showed that boundary-to-boundary scattering in AdS/CFT is only possible when boundary regions associated with the scattering process have order-1/G_N mutual information. From the perspective of quantum information theory, this happens because the boundary theory needs a macroscopic amount of entanglement to simulate the bulk scattering process. I will explain the quantum information intuition in detail, and provide a bulk proof of the theorem using focusing techniques in general relativity. I will also discuss several open directions for future work, including connections to S-matrix singularities and to holographic metric
reconstruction.