MONTE-CARLO RENORMALIZATION OF THE 3D ISING-MODEL - ANALYTICITY AND CONVERGENCE

We review the assumptions on which the Monte Carlo renormalization tec hnique is based, in particular, the analyticity of the block-spin tran sformations. On this basis, we select an optimized Kadanoff blocking r ule in combination with the simulation of a d = 3 Ising model with red uced corrections to scaling. This is achieved by including interaction s with second and third neighbors. As a consequence of the improved tr ansformation, this Monte Carlo renormalization method yields a fast co nvergence and a high accuracy. The results for the critical exponents are y(H) = 2.481(1) and y(T) = 1.585(3).