CONTINUOUS SEQUENCE OF MEAN-FIELD APPROXIMATIONS AND CRITICAL PHENOMENA

The coherent anomaly method, introduced by Suzuki in 1986, provides, in principle, a remarkably simple approach to study critical phenomena within the framework of the mean-field approximation. Unlike the renormalization group techniques commonly employed to investigate critical phenomena, Suzuki's method exploits the systematic behavior of a sequence of mean-field approximations in order to extract critical temperature and exponents. Despite its conceptual simplicity, actual implementation of the CAM requires the ability to treat at least three levels of mean-field approximations belonging to what Suzuki has termed a ''cardinal'' sequence. Here we present a new method based on a continuous sequence of mean-field approximations from which the implementation of the CAM proceeds in a straightforward manner.