Binder cumulant

The Binder cumulant for an Ising model with zero field, is given by

$U_{4}=1-{\frac {\langle m^{4}\rangle }{3\langle m^{2}\rangle ^{2}}}$ .

In the thermodynamic limit, where the system size $L\rightarrow \infty$, $U_{4}\rightarrow 0$ for $T>T_{c}$, and $U_{4}\rightarrow 2/3$ for $T<T_{c}$.

References

1. K. Binder "Finite size scaling analysis of ising model block distribution functions", Zeitschrift für Physik B Condensed Matter 43 pp. 119-140 (1981)