Propagating phase boundaries as sonic horizons
Abstract
Description
If certain conditions are met, a propagating phase boundary can be a sonic horizon. Sonic Hawking radiation from such a phase boundary is expected in the quantum theory. The Hawking temperature for typical values of system parameters can be as large as $\sim 0.04$ K. Since the setup does not require the physical transport of material, it evades the seemingly insurmountable difficulties of the usual proposals to create a sonic horizon in which fluid is required to flow at supersonic speeds. Issues that are likely to present difficulties that are particular to this setup are discussed. Hawking evaporation of the sonic horizon is also expected and is predicted to lead to a deceleration of the phase boundary.
4 pages; added references and some new discussion; corrected numerical estimate of temperature and discussion of AB interface
4 pages; added references and some new discussion; corrected numerical estimate of temperature and discussion of AB interface