BlackHole Horizon and Metric Singularity at the Brane Separating Two Sliding Superfluids
Abstract
An analogue of a black hole can be realized in the lowtemperature laboratory. The horizon can be constructed for "relativistic" ripplons (surface waves) living on the brane. The brane is represented by the interface between two superfluid liquids, ^{3}HeA and ^{3}HeB, sliding along each other without friction. A similar experimental arrangement was recently used for the observation and investigation of the KelvinHelmholtz type of instability in superfluids [1]. The shearflow instability in superfluids is characterized by two critical velocities. The lowest threshold measured in recent experiments [1] corresponds to the appearance of the ergoregion for ripplons. In the modified geometry, this will give rise to the blackhole event horizon in the effective metric experienced by ripplons. In the region behind the horizon, the brane vacuum is unstable due to interaction with the higherdimensional world of bulk superfluids. The time of the development of instability can be made very long at low temperature. This will allow us to reach and investigate the second critical velocity—the proper KelvinHelmholtz instability threshold. The latter corresponds to the singularity inside the black hole, where the determinant of the effective metric becomes infinite.
 Publication:

Soviet Journal of Experimental and Theoretical Physics Letters
 Pub Date:
 September 2002
 DOI:
 10.1134/1.1520613
 arXiv:
 arXiv:grqc/0208020
 Bibcode:
 2002JETPL..76..240V
 Keywords:

 04.50.+h;
 04.70.Dy;
 67.57.De;
 47.20.Ft;
 General Relativity and Quantum Cosmology;
 Condensed Matter;
 High Energy Physics  Phenomenology
 EPrint:
 LaTeX file, 12 pages, 3 Figures, version accepted in JETP Letters