Abstract:
The problem has a large parameter, the number $N$ of particles (outside
the condensate), and a small parameter, Planck's constant $\hbar$
(more precisely, a dimensionless parameter containing $\hbar$ in
the numerator). They turn out to be interrelated for Bose particles. Using
the exact solution of the variational equation for a bosonic system in
a capillary, we can obtain precise criteria restricting the superfluidity of
a classical liquid in the capillary.