Boel, R.J.; Kasteleyn, P.W. - In: Physica A: Statistical Mechanics and its Applications 93 (1978) 3, pp. 503-516
For Ising models with general interactions correlation-function identities of the form ΣBλB〈σB〉〈σBσA〉 = 0 are studied. It is shown that each identity of this form is equivalent to a set of special identities, in which the coefficients λB take only the values -1,0,1. A necessary and...