Black-hole radiation, the fundamental area unit, and the spectrum of particle species

TL;DR

This paper explores the implications of a discrete black hole mass spectrum on its radiation, entropy, and fundamental area unit, highlighting potential impacts on quantum gravity and particle spectra.

Contribution

It analyzes how a discrete black hole spectrum affects entropy emission and the fundamental area unit, providing insights into quantum gravity and the generalized second law.

Findings

Black-hole radiation is less entropic than blackbody radiation.

The entropy emission rate ratio is less than expected, challenging the GSL.

Implications for the fundamental area unit and particle spectrum are discussed.

Abstract

Bekenstein and Mukhanov have put forward the idea that, in a quantum theory of gravity a black hole should have a discrete mass spectrum with a concomitant {\it discrete} line emission. We note that a direct consequence of this intriguing prediction is that, compared with blackbody radiation, black-hole radiance is {\it less} entropic. We calculate the ratio of entropy emission rate from a quantum black hole to the rate of black-hole entropy decrease, a quantity which, according to the generalized second law (GSL) of thermodynamics, should be larger than unity. Implications of our results for the GSL, for the value of the fundamental area unit in quantum gravity, and for the spectrum of massless particles in nature are discussed.