Investigation of Oguchi's procedure applied to the ising model

Abstract

Approximate critical temperature of the anisotropic ferromagnetic Ising model is calculated wing the procedure proposed by Oguchi, with better results than those obtained by the me of Bogolyubov's principle. The calculation is made with linear and double chain trial HamiItonians.Mittels einem von Oguchi angegebenen Vcrfahren wird die geniiherte kritische Temperatur des anisotropen ferromagnetischen Ising-Modells berechnet, und es werden bessere Ergebnisse als mit dem Bogolyubovschen Prinzip crhalten. Dabei werden Test-Hamiltonfunktionen fiir die lineare und doppelte Kette benutzt.

A New Effective Ensemble Approach for the Free Energy

“…Oguchi [ 11 presented a bounded function whose minimum is considered as an approximate free energy. Oguchi's procedure has already been investigated [2]. Further Work partially supported by CNPq and FINEP (Brazilian Agencies).…”