Quasi-particle creation by analogue black holes

TL;DR

This paper explores how analogue black holes in laboratory settings can produce quasi-particles similar to Hawking radiation, showing that a stationary, Planckian emission can occur without an ergoregion, under certain dynamic flow conditions.

Contribution

It demonstrates that a stationary Hawking-like radiation can be generated in analogue black holes without requiring an ergoregion, using simple geometric acoustic models with dynamic flows.

Findings

Stationary, Planckian quasi-particle emission does not require an ergoregion.

Dynamic flow setups can produce Hawking-like radiation asymptotically.

Rapidly changing flows can generate sonic horizons without ergoregions.

Abstract

We discuss the issue of quasi-particle production by ``analogue black holes'' with particular attention to the possibility of reproducing Hawking radiation in a laboratory. By constructing simple geometric acoustic models, we obtain a somewhat unexpected result: We show that in order to obtain a stationary and Planckian emission of quasi-particles, it is not necessary to create an ergoregion in the acoustic spacetime (corresponding to a supersonic regime in the flow). It is sufficient to set up a dynamically changing flow either eventually generating an arbitrarily small sonic region v=c, but without any ergoregion, or even just asymptotically, in laboratory time, approaching a sonic regime with sufficient rapidity.