CRITICAL EXPONENTS FROM POWER SPECTRA

We have simulated the two- and three-dimensional Ising models at their respective critical points with a conventional Monte Carlo algorithm. From the power spectrum of the magnetization autocorrelations we have determined the dynamic critical exponents and obtained the values z=2 .16-2.19 and z=2.05, in agreement with the results quoted in the liter ature. We have also studied the power spectrum for the Kardar-Parisi-Z hang and Sun-Guo-Grant equations describing interface dynamics. Argume nts similar to what was recently used to conclude that z=4-eta for mod el B in critical dynamics were applied to the Sun-Guo-Grant growth mod el and the known exact values for the roughening and dynamic exponents were obtained. From an analysis of the corresponding power spectrum i n self-organized critical sand models one obtains a recently proposed hyperscaling relation.