The Oguchi upper bound on the magnetization for ferromagnetic Ising models

T. Morita

Roger Bowers

J. R. Faleiro Ferreira, N. P. Silva

Abstract Approximate critical temperature of the anisotropic ferromagnetic Ising model is calculated using the procedure proposed by Oguchi, with better results than those obtained by the use of Bogolyubov's principle. The calculation is made with linear and double chain trial Hamiltonians.

George V. Waldo, J. R. Dorfman

Harold Falk

For the quenched spin-1/2 Ising model in a uniform magnetic field and having only nearest-neighbor interactions which are statistically independent non-negative (ferromagnetic) identically distributed random variables, an exact upper bound is obtained for the magnetization. The bound can be identified with the value computed from a generalized Bethe approximation and thereby provides an extension to random interactions of some recent work of Krinsky.

George V. Waldo