DYNAMICAL GLASSY BEHAVIOR ON THE BASIS OF SIMPLE-MODELS DESCRIBED BY MASTER-EQUATIONS

Using a simple Ising model as illustration, general relaxation and evolution properties of systems described by master equations are investigated. The origin of the good agreement obtained by fitting the response function at low temperatures to a stretched exponential is discussed. The details of the freezing process under continuous cooling are analyzed by introducing appropriate timescales and the notion of demarcation mode. For heating processes, the relevance of the concept of normal curves shows up clearly. They explain the appearance of hysteresis cycles and can be useful to interpret experimental results.