Complexity=Action (CA) conjecture: quantum complexity of the boundary state equals the gravitational action on the Wheeler-DeWitt (WDW) patch.
For an eternal AdS-Schwarzschild BH: dC/dt = 2M/ℏ at late times (Lloyd's bound).
Left: Penrose diagram with WDW patch (yellow) at boundary time t. Right: complexity growth vs time.
The WDW patch is the bulk region causally connected to the boundary time slice.