Hawking radiation from AdS black holes

TL;DR

The paper investigates Hartle-Hawking-like equilibrium states of quantum fields on asymptotically AdS black holes, introducing a double Wick-rotation map that connects high-temperature states on AdS black holes to low-temperature states on confining backgrounds such as AdS$_{d}$ solitons or AdS$_3$. It then uses the AdS/CFT correspondence to analyze strongly coupled large-$N$ theories, deriving bulk duals (e.g., black strings and bubbles of nothing) and mapping the phase structure across BTZ and planar AdS black holes. The results show that high-temperature phases on AdS black holes correspond to low-temperature, often confining, phases on the corresponding horizon-free backgrounds, with explicit examples in ${\cal N}=4$ SYM on AdS$_4$ and M2-brane SCFTs on BTZ, including first-order transitions and a linear $q\bar{q}$ potential in certain regimes. These findings partially reconcile puzzles about Hawking radiation and stress-energy behavior in AdS contexts and provide a coherent framework for understanding how confinement-like physics can emerge in strongly coupled theories on curved backgrounds. The work highlights the nuanced relationship between local measurements and global thermodynamics in AdS spacetimes and offers a concrete holographic toolkit for exploringHartle-Hawking-like states on diverse AdS black-hole geometries.

Abstract

We study Hartle-Hawking-like states of quantum field theories on asymptotically AdS black hole backgrounds, with particular regard to the phase structure of interacting theories. By a suitable analytic continuation we show that the equilibrium dynamics of field theories on large asymptotically AdS black holes can be related to the low temperature states of the same field theory on the AdS soliton (or pure AdS) background. This allows us to gain insight into Hartle-Hawking-like states on large-radius Schwarzschild- or rotating-AdS black holes. Furthermore, we exploit the AdS/CFT correspondence to explore the physics of strongly coupled large N theories on asymptotically AdS black holes. In particular, we exhibit a plausibly complete set of phases for the M2-brane world-volume superconformal field theory on a BTZ black hole background. Our analysis partially resolves puzzles previously raised in connection with Hawking radiation on large AdS black holes.