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 ${\xi }^d$. 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.