Numerical tests of local scale invariance in ageing -state Potts models

Institut für Theoretische Physik and Centre for Theoretical Sciences (NTZ), Universität Leipzig Augustusplatz 10/11, 04109 Leipzig, Germany

Received: 20 April 2006
Accepted: 7 November 2006

Abstract

Much effort has been spent over the last years to achieve a coherent theoretical description of ageing as a non-linear dynamics process. Long supposed to be a consequence of the slow dynamics of glassy systems only, ageing phenomena could also be identified in the phase-ordering kinetics of simple ferromagnets. As a phenomenological approach Henkel et al. developed a group of local scale transformations under which two-time autocorrelation and response functions should transform covariantly. This work is to extend previous numerical tests of the predicted scaling functions for the Ising model by Monte Carlo simulations of two-dimensional q-state Potts models with and 8, which, in equilibrium, undergo temperature-driven phase transitions of second and first order, respectively.