Localization of Bose-Einstein Condensation and Disappearance of   Superfluidity of Strongly Correlated Bose Fluid in a Confined Potential
  We develop a Bose fluid model in a confined potential to consider the new quantum phase due to the localization of Bose-Einstein condensation and disappearance of superfluidity which is recently observed in liquid 4He in porous glass at high pressures. A critical pressure of the transition to this phase can be defined by our new analytical criterion of supposing the size of localized Bose-Einstein condensate becomes comparable to the scale of confinement. The critical pressure is quantitatively consistent with observations without free parameters. 
Michikazu Kobayashi and Makoto Tsubota