Observation of self-amplifying Hawking radiation in an analog black hole laser

TL;DR

This paper reports the experimental observation of self-amplifying Hawking radiation in an analog black hole laser created in a Bose-Einstein condensate, confirming key theoretical predictions about black hole radiation.

Contribution

First experimental demonstration of self-amplifying Hawking radiation in an analog black hole laser using a Bose-Einstein condensate.

Findings

Observation of Hawking radiation emitted by the analog black hole

Detection of exponential growth of a standing wave between horizons

Evidence of self-amplifying Hawking radiation

Abstract

It has been proposed that a black hole horizon should generate Hawking radiation. In order to test this theory, we have created a narrow, low density, very low temperature atomic Bose-Einstein condensate, containing an analog black hole horizon and an inner horizon, as in a charged black hole. We observe Hawking radiation emitted by the black hole. This is the output of the black hole laser. We also observe the exponential growth of a standing wave between the horizons. The latter results from interference between the negative energy partners of the Hawking radiation and the negative energy particles reflected from the inner horizon. We thus observe self-amplifying Hawking radiation.