Black hole evaporation rates without spacetime

TL;DR

This paper derives black hole evaporation rates without relying on spacetime, using a thermodynamic and Hilbert space approach, suggesting a spacetime-independent perspective on black hole radiation.

Contribution

It introduces a spacetime-free derivation of black hole evaporation rates based on thermodynamics and symmetries, applicable to extended gravity theories.

Findings

Evaporation rates derived without spacetime assumptions

Applicable to generalized gravity theories with modified area concepts

Highlights the role of symmetries and conservation laws in black hole radiation

Abstract

Verlinde recently suggested that gravity, inertia, and even spacetime may be emergent properties of an underlying thermodynamic theory. This vision was motivated in part by Jacobson's 1995 surprise result that the Einstein equations of gravity follow from the thermodynamic properties of event horizons. Taking a first tentative step in such a program, we derive the evaporation rate (or radiation spectrum) from black hole event horizons in a spacetime-free manner. Our result relies on a Hilbert space description of black hole evaporation, symmetries therein which follow from the inherent high dimensionality of black holes, global conservation of the no-hair quantities, and the existence of Penrose processes. Our analysis is not wedded to standard general relativity and so should apply to extended gravity theories where we find that the black hole area must be replaced by some other property in any generalized area theorem.