AIP conference proceedings
Universality of the Critical Correlations
Martin V. Ferer, Dietrich Stauffer, Michael Wortis, Hugh C. Wolfe, C. D. Graham, James Jennings Rhyne
Abstract
We write the singular parts of the free energy and correlation functions in terms of universal quantities, identical for all members of the same symmetry class, and in terms of two system‐dependent scale‐factors. Besides the universality and homogeneity of the functions, we also assume that the free energy in a volume defined by the correlation length is a universal constant. We can then write the critical singularities of properties derived from these functions in terms of universal quantities and the two scale factors. This two scale‐factor universality has important experimental consequences because once any two properties have been measured for a system the two scale‐factors may be determined via comparison with some reference system in the same symmetry class. Then the remaining properties of the system are predicted by our formalism using the two scale‐factors and the known properties of the reference system. Both our extra assumption and the predictions of two‐scale factor universality are exact for the d = 2 Ising model and agree satisfactorily with results for d = 3 systems.