Published online by Cambridge University Press: 09 April 2009
Expectation values of one-particle and two-particle operators are evaluated in the quasi-chemical equilibrium (pair correlation) approximation to statistical mechanics. Earlier work was restricted to the case of extreme Bose-Einstein condensation of the correlated pairs; the new formulas are not so restricted, but are correspondingly more complicated to evaluate practically. However, a simple result can be obtained for the expectation value of the number of particles.