05.30.Ch Quantum ensemble theory
Refine
Year of publication
- 1986 (1)
Document Type
- Article (1)
Language
- English (1)
Has Fulltext
- yes (1)
Is part of the Bibliography
- no (1)
Institute
- Physik (1)
We formulate a group-theoretical projection technique for the quantum-statistical description of systems with exactly conserved charges corresponding to local non-Abelian gauge symmetries. The formalism is specified for SU(N) internal symmetry and a partition function related to a mixed canonical–grand-canonical ensemble is defined. Its perturbation expansion is derived, and we point out potential applications. We also study single-particle Green’s functions for the calculation of mixed ensemble averages with the help of a generalized Wick’s theorem and find that a connected-graphs expansion is impossible.