T_c for dilute Bose gases: beyond leading order in 1/N

Abstract

Baym, Blaizot, and Zinn-Justin have recently used the large N approximation to calculate the effect of interactions on the transition temperature of dilute Bose gases. We extend their calculation to next-to-leading-order in 1/N and find a relatively small correction of -26% to the leading-order result. This suggests that the large N approximation works surprisingly well in this application.

Comments: 21 pages, 7+1 figures; an embarassing factor of 2 has been corrected in the evaluation of one diagram, changing the previous +18% result for the NLO correction to -26%