Quantum effects in Acoustic Black Holes: the Backreaction

TL;DR

This paper studies the quantum backreaction effects in acoustic black holes formed in Laval nozzles, revealing that phonon radiation causes the sonic horizon to shrink and temperature to decrease, contrasting with classical black hole evaporation.

Contribution

It provides a detailed analysis of backreaction equations for one-dimensional acoustic black holes, showing how phonon radiation influences horizon dynamics and temperature evolution.

Findings

Sonic horizon shrinks as phonons are emitted.

Temperature decreases during phonon radiation.

Behavior differs from classical Schwarzschild black holes.

Abstract

We investigate the backreaction equations for an acoustic black hole formed in a Laval nozzle under the assumption that the motion of the fluid is one-dimensional. The solution in the near-horizon region shows that as phonons are (thermally) radiated the sonic horizon shrinks and the temperature decreases. This contrasts with the behaviour of Schwarzschild black holes, and is similar to what happens in the evaporation of (near-extremal) Reissner-Nordstrom black holes (i.e. infinite evaporation time). Finally, by appropriate boundary conditions the solution is extended in both the asymptotic regions of the nozzle.