Nonperturbative renormalization-group calculations for continuum spin systems

Wilson's exact smooth-cutoff renormalization-group (RG) equation for continuum spin Landau-Ginsburg models is shown to be equivalent to an easily constructed, infinite set of partial differential equations that provide a natural system of successive approximation for numerical calculation. It differs from other RG approaches in that an infinite number of couplings are included at each level of approximation. By way of illustration, preliminary results are presented for Ising-model critical exponents in three dimensions.