Critical velocity of a homogeneous condensate
= Critical velocity of a homogeneous condensate
{title2=$v_L=\sqrt{\mu/m}$}
For a repulsive homogeneous condensate with Bogoliubov <energy> $E(p)=\sqrt{(p^2/2m)(p^2/2m+2\mu)}$, the infimum of $E(p)/p$ is the <speed of sound> $\sqrt{\mu/m}$. This is energetic stability against the given bulk modes, not a universal measured dissipation threshold.