Condensed Matter Physics, 2018, vol. 21, No. 4, 43502
DOI:10.5488/CMP.21.43502
arXiv:1712.07164
Title:
The equation of state of a cell fluid model in the supercritical region
Author(s):

M.P. Kozlovskii
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine)
,


I.V. Pylyuk
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine)
,


O.A. Dobush
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine)

The analytic method for deriving the equation of state of a cell fluid model in the region above the critical temperature (T ≥ T_{c}) is elaborated using the renormalization
group transformation in the collective variables set. Mathematical description with allowance for nonGaussian fluctuations of the order parameter is performed in the vicinity of
the critical point on the basis of the ρ^{4} model. The proposed method of calculation of the grand partition function allows one to obtain the equation for the critical
temperature of the fluid model in addition to universal quantities such as critical exponents of the correlation length. The isothermal compressibility is plotted as a function
of density. The line of extrema of the compressibility in the supercritical region is also represented.
Key words:
cell fluid model, critical exponent, equation of state, supercritical region
PACS:
51.30.+i, 64.60.fd
