CGP Seminarㅣ Operator algebras in AdS/CFT: bulk reconstruction, quantum extremal surfaces, and baby universe

From the AdS/CFT correspondence, we have a holographic isometric map arising between the local operator algebras of the bulk theory and the boundary conformal field theory. I will explain how operator algebras can naturally be used for understanding spacetime theories in this physical context to unveil some structures of quantum gravity. In particular, I will focus on building the formalism on the bulk reconstruction from the boundary operators to the bulk operators and explain how quantum extremal surfaces aid in studying the relative entropy of the bulk and the boundary. I will further describe how we can understand the formulation in low-dimensions to describe the topology changes of the bulk.