Рівняння стану коміркової моделі плину з врахуванням гаусових флуктуацій параметра порядку

• Дата: 2020
• Автори: Pylyuk, I.V., Dobush, O.A.
• Формат: Стаття
• Мова: English
• Опубліковано: Publishing house "Academperiodika" 2020
• Теми: cell fluid model; equation of state; grand partition function; Morse potential; zero-mode approximation; Phase behavior of a simple cell fluid model; equation of state with allowance for Gaussian fluctuations; Фазова поведінка простої коміркової моделі плину; рівняння стану з врахуванням гаусових флуктуацій
• Онлайн доступ: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2020185
• Назва журналу: Ukrainian Journal of Physics

The paper is devoted to the development of a microscopic description of the critical behavior of a cell fluid model with allowance for the contributions from collective variables with nonzero values of the wave vector. The mathematical description is performed in the supercritical temperature range (T > Tc) in the case of a modified Morse potential with additional repulsive interaction. The method, developed here for constructing the equation of state of the system by using the Gaussian distribution of the order parameter fluctuations, is valid beyond an immediate vicinity of the critical point for wide ranges of the density and temperature. The pressure of the system as a function of the chemical potential and density is plotted for various fixed values of the relative temperature, both with and without considering the above-mentioned contributions. Compared with the results of the zero-mode approximation, the insignificant role of these contributions is indicated for temperatures T > Tc. At T < Tc, they are more significant.