A note on the 2D NLSM free energy
arXiv:2606.06277
Abstract
This note contains the perturbative computation of the 2D non-linear sigma model (NLSM) energy-density in a chemical potential , at the fourth order in the coupling constant expansion. The result is in fully agreement with the asymptotics extracted from the thermodynamical Bethe ansatz (TBA).
1 figure, 15 pages