Acoustic Hawking radiation as a tunneling effect in Michel accretion
Phys. Rev. D 114, 063058 – Published 28 September, 2026
DOI: https://doi.org/10.1103/mgfs-g4d3
Abstract
Michel accretion becomes transonic at the saddle point of a dynamical system. An Eulerian perturbation on the steady inflow produces the metric of an acoustic black hole. As a high-frequency traveling wave the perturbation does not destabilize the steady inflow. Acoustic waves propagating outward against the fluid inflow are blocked at the sonic barrier but can tunnel through it with an exponentially decaying amplitude. The Hawking temperature and the frequency of the Hawking phonons are augmented by the spacetime geometry.
