<Original Papers>Studies of relations between many-body problems and green functions: green function and many-body problems (11) Quantum statistical mechanics (3)

ln this paper, next subject is discussed, §32. The equation of state of an ideal gas. Here we consider the equation of state of a spinless ideal Fermi gas. ln high temperatures and low density, we obtain the form of a virial expansion of the equation of state. The corrections to the classical ideal gas law are due to quantum effects. The second virial coefficient is deduced. In low temperature and high densities, we obtain the expansion for the chemical potential in the expansion parameter /. Next we obtain the asynptotic expansion of the internal energyU in the expansion parameter /. We also obtain the specific heat at constant volume C_V.