(1) Department of Theoretical Physics, IFIN, Central Institute of Physics, Bucharest-Magurele, Romania;(2) INCREST, B-dul Pacii 220, 79622 Bucharest, Romania
Abstract:
For an exactly soluble classical spin model with long-range inhomogeneous coupling it is proved that in the absence of external magnetic field the free energy is aC function of the temperature at the critical point.