Thermodynamic Critical Fluctuation Theory?

The conventional thermodynamic fluctuation theory does not include local correlations and, hence, fails at volumes of the order of the correlation volume ξᵈ. In this paper, an attempt is made to include local correlations in a thermodynamic theory by considering fluctuations in a sequence of concentric systems of decreasing volume. Tests are made on fluctuations in the magnetization within the one-dimensional Ising model. The results are a clear improvement over those of the conventional theory.