| תקציר: | Studies of sonic analog black holes have concentrated on (1+1)-dimensional scenarios, but Unruh's analogy is only strictly valid in more than one spatial dimension. We simulate a sonic black-hole / white-hole pair in a (2+1)-dimensional Bose-Einstein condensate and observe the formation of many superfluid vortices through dynamical instabilities seeded by simulated quantum noise. The turbulent ergoregion radiates sound but it is not thermal. Our results show that the Hawking effect is in principle vulnerable to short-distance physics and that observing it with quantum gases may be more difficult than previously hoped. |