Physical Review B - Condensed Matter and Materials Physics
We apply the nonperturbative optimized linear δ expansion method to the O(N) scalar field model in three dimensions to determine the transition temperature of a dilute homogeneous Bose gas. Our results show that the shift of the transition temperature ΔTc/Tc of the interacting model, compared with the ideal-gas transition temperature, really behaves as γan1/3 where a is the s-wave scattering length and n is the number density. For N=2 our calculations yield the value γ=3.059.
de Souza Cruz, Frederico F.; Pinto, Marcus B.; and Ramos, Rudnei O., "Transition Temperature for Weakly Interacting Homogeneous Bose Gases" (2001). Open Dartmouth: Faculty Open Access Articles. 1945.