Do Evaporating 4D Black Holes Form Photospheres and/or Chromospheres?

TL;DR

This paper critically examines models suggesting that evaporating 4D black holes develop photospheres or chromospheres due to particle interactions, concluding that such effects do not significantly alter Hawking radiation signatures.

Contribution

The paper provides a detailed analysis showing that proposed photosphere and chromosphere formation models around black holes are physically invalid, reaffirming the robustness of standard Hawking emission predictions.

Findings

Photosphere and chromosphere models are invalidated by physical and geometrical effects.

Standard Hawking radiation signatures remain largely unchanged.

Detection probabilities of black hole emissions are not significantly affected.

Abstract

Several authors have claimed that the observable Hawking emission from a microscopic black hole is significantly modified by the formation of a photosphere or chromosphere around the black hole due to QED or QCD interactions between the emitted particles. Analyzing these models we identify a number of physical and geometrical effects which invalidate them. In all cases, we find that the observational signatures of a cosmic or Galactic background of black holes or an individual black hole remain essentially those of the standard Hawking model, with little change to the detection probability.