Asymptotic behavior of model systems with positive interactions and sources

The class of model systems of equilibrium statistical physics with positive inter­ action of the type Jj^+ and sources in the limit of the unbounded system is investi­ gated. It is shown that the interaction results in weakening of the sources. It is found that phase transitions of a certain type are absent in the model systems considered. The results are illustrated with reference to a concrete model.