Black Hole Greybody Factors and D-Brane Spectroscopy

TL;DR

This paper demonstrates that greybody factors modify black hole radiation spectra to match the energy spectrum of D-brane bound states, providing insights into black hole information dynamics.

Contribution

It shows how greybody factors transform blackbody radiation into the D-brane bound state spectrum for near-extremal black holes.

Findings

Greybody factors convert blackbody spectrum into bound state spectrum

Results apply to both neutral and charged emissions

Implications for black hole information puzzle

Abstract

Black holes do not Hawking radiate strictly blackbody radiation due to well-known frequency-dependent greybody factors. These factors arise from frequency-dependent potential barriers outside the horizon which filter the initially blackbody spectrum emanating from the horizon. D-brane bound states, in a thermally excited state corresponding to near-extremal black holes, also do not emit blackbody radiation: The bound state radiation spectrum encodes the energy spectrum of its excitations. We study a near-extremal five-dimensional black hole. We show that, in a wide variety of circumstances including both neutral and charged emission, the effect of the greybody filter is to transform the blackbody radiation spectrum precisely into the bound state radiation spectrum. Implications of this result for the information puzzle in the context of near-extremal black hole dynamics are discussed.