2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114699We consider the nonrelativistic interacting Bose gas at zero and finite temperature. Using the 1/N-expansion, we derive expressions for the free energy density and the number density to next-to-leading order in 1/N. Outside the critical region and at weak coupling, our calculations reduce to the well-known mean-field results for the dilute Bose gas. We also rederive the nonperturbative critical density for Bose condensation which was first calculated by Baym, Blaizot, Holzmann, Lalöe, and Vautherin.6 pages, 3 figsOther Condensed MatterHigh Energy Physics - Phenomenologytext