Charting the scaling region of the Ising universality class in two and three dimensions

Understand

We study the behaviour of a universal combination of susceptibility and correlation length in the Ising model in two and three dimensions, in presence of both magnetic and thermal perturbations, in the neighbourhood of the critical point.

• In three dimensions we address the problem using a parametric representation of the equation of state.
• In two dimensions we make use of the exact integrability of the model along the thermal and the magnetic axes.
• Our results can be used as a sort of "reference frame" to chart the critical region of the model.