GAUSSIAN, NON-GAUSSIAN CRITICAL FLUCTUATIONS IN THE CURIE-WEISS MODEL

It is known that at the critical temperature the Curie-Weiss mean-fiel d model has non-Gaussian fluctuations and that ''internal fluctuations '' can be Gaussian. Here we compute the distribution of the q-mode mag netization fluctuations as a function of the temperature, the wave vec tor q, and a fading out external field. We obtain new classes of proba bility distributions generated by this external field as well as new c ritical behavior in terms of its rate of fading out. We discuss also t he susceptibility as the limit q tending to zero.