  The Ising model doesn't have a strictly defined dynamics, only a spectrum.
There are different ways to equip it with a time dependence e.g. the Glauber or
the Kawasaki dynamics, which are both stochastic, but it means there is a
master equation which can also describes their dynamics. We present a
Gluber-type master equation derived from the Redfield equation, where the spin
system is coupled to a bosonic bath. We derive a time dependent mean field
equation which describes the relaxation of the spin system at finite
temperature. Using the fully connected, uniform Ising model the relaxation time
will be studied, and the critical behaviour around the critical temperature.
The master equation shows the finite size effects, and the mean field equation
the thermodynamic limit.
