Condensed Matter Physics, 2009, vol. 12, No. 4, pp. 581592
DOI:10.5488/CMP.12.4.581
Title:
The Bogolyubov method of quasiaverages solves the problem of pressure fluctuations in the Gibbs statistical mechanics
Author(s):

Yu.G. Rudoy
(People's Friendship University, 117198, 6 MiklukhoMaklaya Str., Moscow, Russia)

The longstanding and highly nontrivial problem of calculating the pressure fluctuations in the Gibbs equilibrium statistical mechanics is fully revised. The previous attempts are critically analyzed and it is shown that the application of the ideas by Bogolyubov gives the full and unambiguous solution of this problem. The crucial role is played by the Bogolyubov's idea of quasiaverages (or rather quasidynamic) quantities  specifically, the pressure P and dynamic compressibility Ψ. The virtual conjugate field which eliminates the translational invariance of the Hamilton function H in the limit ε→ 0 is the singular potential of the impenetrable walls of the container. The general relations for P and Ψ in terms of the derivatives of H are obtained and some examples are studied  i. e., the cases of the ideal vs. nonideal as well as of uniform vs. non and quasiuniform (in Euler sense) Hamilton function H describing the given system.
Key words:
Gibbs equilibrium statistical mechanics, Bogolyubov's quasiaverages, pressure fluctuations, relativistic ideal gas
PACS:
05.70.a, 05.30.d, 05.40.a
