Title：Entanglement Islands in Braneworlds

Speaker：Hao Geng

Time：March 15,202120：00（Beijing Time）

Venue：302，Physics Building

Online report（ZOOM ID：893 4991 8147 Passcode: 369963）

Abstract：In this talk, I'll introduce various results of my recent research on entanglement islands in the braneworlds. These are the only existing reliable models of entanglement islands in general dimensions. To start the journey, I'll describe the resolution of an information paradox for black holes in the Karch-Randall braneworld using its doubly holographic description. We coupled the black hole to a bath and we analytically determined the location of the entanglement island of the radiation region. However, this coupling induces mass for gravitons and hence modifies the gravitational theory. A straightforward proposal to rectify this massive graviton problem is to make the bath gravitating. Nevertheless, due to the non-factorizablity of the Hilbert space, this disenables us to ask the question of the fine-grained entanglement entropy of the black hole radiation absorbed by the bath. This raises the question wondering the level at which Hawking's information paradox is or can be resolved by AdS/CFT. Interestingly, when we consider De-Sitter holography, in the framework of the DS/dS correspondence, we find that the coupling between the bath and a De-Sitter space doesn’t induce mass for the gravitons, the non-factorizability argument doesn't persist and using the island rule we get a consistently unitary Page curve.

Brief Bio：Hao Geng is currently working at University of Washington. His research interest is theoretical physics.