A comparative study of the dynamic critical behavior of the four-state Potts like models.

We investigate the short-time critical dynamics of the Baxter?Wu (BW) and n=3 Turban (3TU) models to estimate their global persistence exponent ?g. We conclude that this new dynamical exponent can be useful in detecting differences between the critical behavior of these models which are very difficult to obtain in usual simulations. In addition, we estimate again the dynamical exponents of the four-state Potts (FSP) model in order to compare them with results previously obtained for the BW and 3TU models and to decide between two sets of estimates presented in the current literature. We also revisit the short-time dynamics of the 3TU model in order to check if, as already found for the FSP model, the anomalous dimension of the initial magnetization x0 could be equal to zero