On the Interaction Representation
Yoshinori Takahashi, Hiroomi Umezawa · Progress of Theoretical Physics · 1952
Progress of Theoretical Physics Vol. 74 No. 2 (1985) pp. 429-432 A General Formulation of Nonequilibrium Thermo Field Dynamics T. Arimitsu and H. Umezawa Progress of Theoretical Physics Vol. 77 No. 1 (1987) pp. 32-52 Non-Equilibrium Thermo Field Dynamics Toshihico Arimitsu and Hiroomi Umezawa