Theory of a Charged Boson Gas Using the Random-Phase Approximation

The Brandow boson many-body theory is used to calculate the generalized dielectric constant within the random-phase approximation. The generalized dielectric constant obtained this way agrees with the Bogoliubov theory in the high-density limit and thus yields all of the well-known Bogoliubov results. The momentum distribution function for $\overrightarrow{\mathrm{k}}\ne 0$ is also calculated. The treatment is fully number conserving.