Time Evolution of Entanglement Entropy from Black Hole Interiors

Understand

We compute the time-dependent entanglement entropy of a CFT which starts in relatively simple initial states.

• The initial states are the thermofield double for thermal states, dual to eternal black holes, and a particular pure state, dual to a black hole formed by gravitational collapse.
• The entanglement entropy grows linearly in time.
• This linear growth is directly related to the growth of the black hole interior measured along "nice" spatial slices.