Quantum Cross-section of Near-extremal Black Holes
arXiv:2501.17470 · doi:10.1007/JHEP04(2025)122
Abstract
We explore how to detect the large quantum fluctuations in the throat of a near-extremal black hole, where the dynamics are governed by the Schwarzian theory. To this end, we scatter a low-frequency wave of a massless, minimal scalar off the black hole and calculate the absorption cross-section. In the semiclassical regime, where the Schwarzian is weakly coupled, we recover the universal result that the cross-section equals the horizon area. However, in the strongly coupled regime, where quantum fluctuations dominate, we find that the absorption cross-section exceeds the semiclassical prediction. This result may seem counterintuitive, given that the density of black hole states is suppressed in this regime. Nevertheless, two effects outweigh this suppression. First, quantum fluctuations enhance absorption transitions between individual states, with the effect becoming stronger closer to the ground state. Second, these fluctuations significantly reduce stimulated emission. We conclude that a measurement showing an enhanced absorption cross-section serves as a clear signature of the large quantum fluctuations in the geometry.
arXiv comment16 pages, 3 figures. v2: minor changes. v3: small improvements and refs added. Matches published version
References in corpus (26)
- Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
- Shear viscosity of strongly coupled N=4 supersymmetric Yang-Mills plasma
- Charged AdS Black Holes and Catastrophic Holography
- Black Hole Greybody Factors and D-Brane Spectroscopy
- Fermionic Localization of the Schwarzian Theory
- Universailty of Low Energy Absorption Cross-sections for Black Holes
- Comparing decay rates for black holes and D-branes
- Solving the Schwarzian via the Conformal Bootstrap
- Universal Low-Energy Dynamics for Rotating Black Holes
- Solvable Models of Quantum Black Holes: A Review on Jackiw-Teitelboim Gravity
- The Quantum Gravity Dynamics of Near Extremal Black Holes
- Statistical mechanics of a two-dimensional black hole
- An exact quantization of Jackiw-Teitelboim gravity
- A universal Schwarzian sector in two-dimensional conformal field theories
- Four-dimensional greybody factors and the effective string
- Absorption of Fixed scalars and the D-brane Approach to Black Holes
- Can the effective string see higher partial waves?
- Jackiw-Teitelboim Gravity and Rotating Black Holes
- Emission of charged particles from four- and five-dimensional black holes
- Absorption of angular momentum by black holes and D-branes
- Hydrodynamics of cold holographic matter
- Towards Black Hole Evaporation in Jackiw-Teitelboim Gravity
- Logarithmic Corrections to Kerr Thermodynamics
- Unruh detectors and quantum chaos in JT gravity
- Tearing down spacetime with quantum disentanglement
- Near-Extremal Charged Black Holes: Greybody Factors and Evolution