Bose Condensation in Superconductors and Liquid ⁴He

Abstract

Calculations on many-body systems containing both composite particles and their constituents are facilitated by the use of representations^1–3 in which the composite particles are described in terms of their own dynamic variables. The method³ we shall employ here is based on the familiar idea of the introduction of initially redundant variables corresponding to the composite particles, followed by a canonical transformation which gives these extra modes physical content. This approach is similar to that employed, e.g., in the Bohm—Pines theory of plasma oscillations,⁴ in which extra plasmon variables were introduced.

Supported by National Science Foundation grant GP-11728.