Enhanced Geometry Fluctuations in Minkowski and Black Hole Spacetimes

TL;DR

This paper examines how spacetime geometry fluctuations, especially near black hole horizons, affect observable phenomena like luminosity and spectral lines, and finds that black hole thermal properties are surprisingly resilient to such fluctuations.

Contribution

It investigates the impact of enhanced horizon fluctuations on black hole thermality, showing the robustness of Hawking radiation against these effects.

Findings

Horizon fluctuations can cause luminosity variations and spectral broadening.

Black hole thermal radiation remains stable despite enhanced horizon fluctuations.

Operational signatures of geometry fluctuations include image distortions and angular blurring.

Abstract

We will discuss selected physical effects of spacetime geometry fluctuations, especially the operational signatures of geometry fluctuations and their effects on black hole horizons. The operational signatures which we discuss involve the effects of the fluctuations on images, and include luminosity variations, spectral line broadening and angular blurring. Our main interest will be in black hole horizon fluctuations, especially horizon fluctuations which have been enhanced above the vacuum level by gravitons or matter in squeezed states. We investigate whether these fluctuations can alter the thermal character of a black hole. We find that this thermal character is remarkably robust, and that Hawking's original derivation using transplanckian modes does not seem to be sensitive even to enhanced horizon fluctuations.