In the mean-field approximation, the partition function of the Ising model is given by
ₘF=⁻m²/²(2coℎ(ℎₑ)), where denotes the number of neighbors per spin site, m is the magnetization and ℎₑ= ℎ+m.
Using the partition function, show that the mean-field approximation leads to the self-consistency equation m=ℎ[(ℎ+m)].