Journal of Statistical Physics, Vol. 75, Nos. 5/6, 1994. p. 1179-1184.
Upper bounds on the decay of various correlation functions are derived for a general class of itinerant fermion models with long-range hopping matrix. These bounds extend previous results of Koma and Tasaki and rule out the possibility of magnetic ordering and condensation of superconducting electron pairs in one and two dimensions for finite temperatures.