It's defined on page 5. > In this paper we are considering the behaviour of ∆(HΛ(L)) in the thermodynamic limit, that is, when L → ∞ So it's the same as the r

It's defined on page 5. > In this paper we are considering the behaviour of ∆(HΛ(L)) in the thermodynamic limit, that is, when L → ∞ So it's the same as the regular mathematical limit. There must be some thermodynamic implications but my knowledge of physics is not enough to say.