Numerical Studies of Sonic Black and White Holes
The videos show pairs of sonic black and white holes in a 1D/2D BEC. The BEC is flowing from the left to the right with a constant velocity. The speed of sound is tuned in a way that we obtain two subsonic and a supersonic region. The surfaces where the flow velocity equals the speed of sound are called sonic horizons and are indicated by dashed lines. The left line is the black hole horizon whereas the right line is the white hole horizon. The videos show the absolute value (“Betrag”) and the phase (“Phase”) of the macroscopic wave function Ψ. At the beginning of the simulations a dynamical instability is excited which grows and leads to the emisson of solitons (1D) or vortices (2D) out of the white hole horizon. This process finally kills the black and white hole because the solitons and vortices carry away energy from the supersonic region, which is in turn slowed down until the flow velocity reaches a constant value less than the speed of sound. Further details can be found in my diploma thesis.