Long-range correlations in the statistical theory of critical fluid

V. N. Bondarev

Published 2019-09-26Version 1

Using the approach formulated in the previous papers of the author, a consistent procedure is developed for calculating non-classical asymptotic power terms in the total and the direct correlation functions of a critical fluid. Analyzing the Ornstein-Zernike equation allows us to find, for the first time, the values of transcendental exponents 1.73494 and 2.26989 which determine the asymptotic terms next to the leading one in the total correlation function. It is shown that already the simplest approximation based on only two asymptotic terms leads to the correlation functions, which are quantitatively close to the corresponding ones of the Lennard-Jones fluid (argon) in the near-critical state. The obtained results open a way for consistent theoretical interpretation of the experimental data on the critical characteristics of real substances. Both the theoretical arguments and analysis of published data on the experimentally measured critical exponents of real fluids lead to the conclusion that the known assumption of the sameness of the critical characteristics of the Ising model and the fluid in the vicinity of critical point (the universality hypothesis) should be questioned.