Density dependence of the transition temperature in a homogeneous Bose-Einstein condensate

Transition temperature data obtained as a function of particle density in t he He-4-Vycor system are compared with recent theoretical calculations for 3D Bose-condensed systems. In the low density dilute Bose gas regime we fin d, in agreement with theory, a positive shift in the transition temperature of the form Delta T/T-0 = gamma(na(3))(1/3). At higher densities a maximum is found in the ratio of T-c/T-0 for a value of the: interaction parameter , na(3), that is in agreement with path-integral Monte Carlo calculations.