Solvable Models of Quantum Black Holes: A Review on Jackiw-Teitelboim Gravity

TL;DR

This review presents JT gravity as a tractable, solvable laboratory for quantum gravity, unifying classical dilaton gravity, a boundary Schwarzian description, and exact quantum path integrals. It details how boundary dynamics encode bulk physics, the role of spacetime wormholes and random matrices in resolving information-loss puzzles, and how matter, defects, and gauge fields extend the JT framework. The work highlights key results on black hole spectra, OTOCs, entanglement islands, and the island/replica program, while outlining generalizations to supersymmetric JT, Liouville gravity, and minimal strings. Collectively, JT gravity provides deep insights into holography, ensemble averaging, and the quantum structure of spacetime, with broad implications for chaos, information recovery, and quantum cosmology.

Abstract

We review recent developments in Jackiw-Teitelboim (JT) gravity. This is a simple solvable model of quantum gravity in two dimensions (that arises e.g. from the s-wave sector of higher dimensional gravity systems with spherical symmetry). Due to its solvability, it has proven to be a fruitful toy model to analyze important questions such as the relation between black holes and chaos, the role of wormholes in black hole physics and holography, and the way in which information that falls into a black hole can be recovered.

Figures (19)

• Figure 1: Spatial geometry of the Reissner-Nordstrom black hole which interpolates between flat space far away and an AdS${}_2\times$S${}^2$ throat near the horizon when the temperature is low. The size of the black hole is of order $Q$ (in appropriate units) while the length of the AdS${}_2\times$S${}^2$ throat diverges as we approach extremality. JT gravity arises as a sector of Einstein-Maxwell in 4d and is the dominant mode controlling the low energy dynamics taking place inside the throat. This is true for a large class of black holes with AdS${}_2\times$S${}^2$ throats.
• Figure 2: Penrose diagram with the different classical patches of global AdS$_2$.
• Figure 3: Penrose diagram of AdS$_2$ in the Poincaré patch. An energy pulse is injected at time $T=0$, indicated in red.
• Figure 4: Penrose diagram of AdS$_2$ in Poincaré patch before and after injecting an energy pulse. In red we show the boundary trajectory. We see this gets kicked after the insertion in such a way that a black hole horizon appears.
• Figure 5: Cutout of the Poincaré upper half plane.