EFFECT OF STATISTICAL FLUCTUATIONS ON CONFINEMENT AND ON THE VACUUM STRUCTURE OF THE CPN-1 MODELS

We study the two-dimensional CPn-1 non-linear σ-models at a finite temperature, T, within the 1/n expansion. We show that permanent confinement of their fundamental particles is a strictly zero-temperature phenomenon. The quantum statistical fluctuations suppress the non-trivial topological structure of the classical CPn-1 models and consequently the background topological density vanishes at T ≠ 0 for an infinite space volume". These models do not depend on the vacuum angle θ at any T ≠ 0. © 1979."