Coleman's theorem on physical assumptions for no Goldstone bosons in two dimensions

Abstract

Thirty years ago, Coleman proved that no continuous symmetry is broken spontaneously in a two-dimensional relativistic quantum field theory. In his argument, however, it is difficult to understand the physical meaning of the assumption of no infrared divergence. I derive the same result directly from the cluster property of a local field regarded as a physically acceptable assumption.

7 pages, no figures, corrected serious errors