Universality in short-range Ising spin glasses

The role of the distribution of coupling constants in the critical exponent s of the short-range Ising spin-glass model is investigated via real space renormalization group. A saddle-point spin glass critical point characteriz ed by a fixed-point distribution is found in an appropriated parameter spac e. The critical exponents beta and nu are directly estimated from the data of the local Edwards-Anderson order parameters for the model defined on a d iamond hierarchical lattice of fractal dimension d(f) = 3. Four distinct in itial distributions of coupling constants (Gaussian, bimodal, uniform and e xponential) are considered; the results clearly indicate a universal behavi our. (C) 1999 Elsevier Science B.V. All rights reserved.