In gauge/gravity duality, matrix degrees of freedom on the QFT side play important roles for the emergent geometry.
In this talk, we discuss how the entanglement in the gravity side can be described as the entanglement between matrix degrees of freedom.
Our approach is different from 'target-space entanglement' which was proposed recently by several groups. The examples studied include the evaporation of small black hole, to which our approach provides a natural QFT counterpart of the entanglement island behind the horizon. Specifically, we propose that the confined degrees of freedom in the partially-deconfined states are the counterpart of the island. Intuitively, the confined sector consists of D-branes sitting behind the horizon and sourcing the exterior geometry. In the context of ER=EPR conjecture, they play the role of Einstein-Rosen bridge.
Our proposal applies to the standard gauge/gravity duality such as AdS5/CFT4 correspondence, and does not require heat bath.
This talk is based on work in progress with Vaibhav Gautam, Antal Jevicki and Cheng Peng.
