Interaction of Hawking radiation with static sources outside a Schwarzschild black hole

TL;DR

This paper demonstrates the equivalence of response rates between static sources near a Schwarzschild black hole and uniformly accelerated sources in flat spacetime, highlighting the effects of different quantum vacua on Hawking radiation interactions.

Contribution

It reveals the conditions under which the response rates of static and accelerated sources are equal, and how different vacua influence this interaction in black hole spacetimes.

Findings

Response rate matches between static sources in Schwarzschild spacetime and accelerated sources in Minkowski spacetime.

Equality holds in the Unruh vacuum but not in the Hartle-Hawking vacuum.

Response near the horizon mimics a thermal bath at the Hawking temperature.

Abstract

We show that the response rate of (i) a static source interacting with Hawking radiation of massless scalar field in Schwarzschild spacetime (with the Unruh vacuum) and that of (ii) a uniformly accelerated source with the same proper acceleration in Minkowski spacetime (with the Minkowski vacuum) are equal. We show that this equality will not hold if the Unruh vacuum is replaced by the Hartle-Hawking vacuum. It is verified that the source responds to the Hawking radiation near the horizon as if it were at rest in a thermal bath in Minkowski spacetime with the same temperature. It is also verified that the response rate in the Hartle-Hawking vacuum approaches that in Minkowski spacetime with the same temperature far away from the black hole. Finally, we compare our results with others in the literature.