Chiral symmetry, the 1/N expansion and the SU(N) thirring model

In the two-dimensional SU(N) Thirring model, the 1/N expansion seems to predict spontaneous breaking of the continuous chiral symmetry. This is impossible in two-dimensions. Reasoning along the lines of Berezinski, Kosterlitz and Thouless for the two-dimensional XY model, we argue that, in fact, rather than showing long-range order, 〈ψψ(x) ψψ(0)〉 vanishes in this model as |x|−1/N at large |x|. The 1/N expansion is, in fact, a rather good guide to the properties of this model.