Independent replication of spontaneous Hawking radiation in an atomic condensate
In plain words
One laboratory has reported that a flowing Bose-Einstein condensate (a gas cooled until its atoms move in lockstep) emits Hawking-like sound from quantum fluctuations alone. The question is whether a second, independent group sees the same emission with the predicted temperature.
Precise statement
In a quasi-one-dimensional atomic BEC with a stationary sonic horizon (step potential or waterfall configuration), measure the equal-time density-density correlation G2(x, x') and extract the Hawking-partner correlation band across the horizon and its Fourier spectrum. An answer is an observation by a group other than the Technion group at high statistical significance of a stationary correlation band whose spectrum matches $T_{H}=\hbar \kappa/(2\pi)$ for the measured $\kappa$, with stimulated contributions (initial thermal phonons, black-hole-laser amplification, Bogoliubov-Cherenkov emission from obstacles) quantitatively excluded.
What would settle it
An independent atomic-BEC experiment reproducing the stationary Hawking correlation band and its spectrum with a measured surface gravity.
Status in the literature
Unverified note
Spontaneous emission has been reported only by Steinhauer's group (2016, 2019, and a 2021 stationarity study); to the extent checked, no independent atomic-BEC replication is reported as of 2026.