Influence of long-range effects on the critical behavior of three-dimensional systems

The Pade-Borel resummation technique is used to describe field-theoretically, in the two-loop approximation, the behavior of Ising systems with long-range effects directly in a three-dimensional space. The renormalization-group equations are analyzed and the fixed points governing the critical behavior of the system are determined. It is shown that the long-range effects can bring about a change in both the regime of critical behavior and the kind of phase transition. (C) 2003 MAIK Nauka/Interperiodica.