Jo. Andersen et M. Strickland, Application of renormalization-group techniques to a homogeneous Bose gas at finite temperature, PHYS REV A, 60(2), 1999, pp. 1442-1450
A homogeneous Bose gas is investigated at finite temperature using renormal
ization-group techniques. A nonperturbative flow equation for the effective
potential is derived using sharp and smooth cutoff functions. Numerical so
lutions of these equations show that the system undergoes a second-order ph
ase transition in accordance with universality arguments. We obtain the cri
tical exponent nu = 0.73. [S1050-2947(99)09007-1].