The application of Quantum Field Theory for Lennard-Jones fluid

The paper deals the mathematical model of weakly coupled high degenerate qu antum fluid. We try to calculate the thermodynamical properties of state fo r the Lennard-Jones fluid with help of quantum field theory of many particl e systems and finite temperature formalism. We used Feynman-Dyson perturbat ion theory. We developed an expression for the grand potential with help of temperature Green functions and Feynman diagrams. The results of the analy sis are compared with experimental data and other models and shout a relati vely good agreement. This model is the first experiment for calculating the thermodynamical functions of refrigerants at temperatures T>>0K.