The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the $\\alpha$ --degree of freedom to tilde non--conserving representations is considered. Secondly, the usual $2\\times2$ Bogoliubov matrix is extended to a $4\\times4$ matrix including mixing of modes with non--trivial multiparticle correlations. The analysis is carried out for both bosons and fermions.The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the $\\alpha$--degree of freedom to tilde non--conserving representations is considered. Secondly, the usual $2\\times2$ Bogoliubov matrix is extended to a $4\\times4$ matrix including mixing of modes with non--trivial multiparticle correlations. The analysis is carried out for both bosons and fermions.

Jan 1, 199311 citations

The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the

\\alpha

--degree of freedom to tilde non--conserving representations is considered. Secondly, the usual

2\\times2

Bogoliubov matrix is extended to a

4\\times4

matrix including mixing of modes with non--trivial multiparticle correlations. The analysis is carried out for both bosons and fermions.