An inequality for the density of condensate atoms in superfluid 4He
Pitaevskii L.P.
An inequality setting an upper limit on the density of the condensate of a superfmid Bose fluid at Τ ~ 0 is derived. In the derivation advantage was taken of the fact that the excited states with к φ 0 are separated from the ground state by a finite gap. A numerical calculation for 4He yields n0/n <0.77.