Radiation from the non-extremal fuzzball

TL;DR

This paper demonstrates that the classical instability of certain non-extremal fuzzball geometries corresponds exactly to Hawking radiation, providing a gravity-based description of information-carrying radiation from black hole microstates.

Contribution

It establishes a direct link between the classical instability of non-extremal fuzzball geometries and Hawking radiation, showing how microstate-specific emission can be understood within gravity.

Findings

Classical instability matches Hawking radiation emission.

Microstates exhibit Bose-Einstein condensate behavior.

Radiation from microstates is enhanced and information-rich.

Abstract

The fuzzball proposal says that the information of the black hole state is distributed throughout the interior of the horizon in a `quantum fuzz'. There are special microstates where in the dual CFT we have `many excitations in the same state'; these are described by regular classical geometries without horizons. Jejjala et.al constructed non-extremal regular geometries of this type. Cardoso et. al then found that these geometries had a classical instability. In this paper we show that the energy radiated through the unstable modes is exactly the Hawking radiation for these microstates. We do this by (i) starting with the semiclassical Hawking radiation rate (ii) using it to find the emission vertex in the CFT (iii) replacing the Boltzman distributions of the generic CFT state with the ones describing the microstate of interest (iv) observing that the emission now reproduces the classical instability. Because the CFT has `many excitations in the same state' we get the physics of a Bose-Einstein condensate rather than a thermal gas, and the usually slow Hawking emission increases, by Bose enhancement, to a classically radiated field. This system therefore provides a complete gravity description of information-carrying radiation from a special microstate of the nonextremal hole.