Effective field methods in lattice systems
Raf Dekeyser, G. Kamieniarz
Abstract
It is possible to generalise in several ways the sefconsistency conditions inherent in the mean field approximation. One can then obtain a substantial improvement on the estimates of critical parameters through rather simple calculations; also critical exponents can be obtained through a combination with the mean-field renormalization group method. These techniques can also be applied to quantummechanical systems.