On Complexity of Jackiw-Teitelboim Gravity
Mohsen Alishahiha
TL;DR
This work analyzes holographic complexity in Jackiw-Teitelboim gravity using the complexity=action proposal. By implementing a UV regularization that induces a behind-horizon cutoff (à la Akhavan), the authors compute the on-shell Wheeler-DeWitt action for an AdS$_2$ black hole with a linear dilaton and show that the complexity grows linearly at late times, in contrast to earlier constant-velocity results. The analysis is extended to a general 2D dilaton gravity, where fluctuations about a constant dilaton reduce to JT dynamics and a topological boundary term crucially contributes to the complexity, yielding near-extremal growth rates that match expectations from charged higher-dimensional reductions. For a concrete potential derived from dimensional reduction of 4D Maxwell-Einstein gravity, the late-time rate takes the form $\frac{dI}{d\tau}=S_0 T+\frac{\pi \ell}{G} T^2$, illustrating near-extremal behavior and reinforcing the role of boundary terms in CA complexity. Overall, the results highlight sensitivity of CA complexity to regularization and boundary terms and suggest consistency with holographic descriptions of nearly conformal systems such as the SYK model.
Abstract
Using "complexity=action" proposal we compute complexity for Jackiw-Teitelboim gravity assuming that a UV cutoff enforces us to have a cut off behind the horizon. We find that the resultant complexity exhibits the late time linear growth. It is also consistent with the case where the corresponding Jackiw-Teitelboim gravity is obtained by dimensional reduction from higher dimensional gravities. To this work certain counter term on the cut off surface behind horizon is needed.
