TY - JOUR
T1 - Linear response in non-equilibrium thermo field dynamics
AU - Nakamura, K.
AU - Yamanaka, Y.
AU - Umezawa, H.
N1 - Funding Information:
The authors would like to thank Drs. T. Arimitsu and I. Hardman for valuable discussions.T his work was supported by the Natural Sciences and Engineering Research Council, Canada and the Dean of Science, Faculty of Science, the University of Alberta.
PY - 1988/9
Y1 - 1988/9
N2 - The linear response theory is discussed in the context of non-equilibrium thermo field dynamics which has been developed in recent years and can deal with a quantum field system in time-dependent non-equilibrium situations. An example of a simple model is given to illustrate the present formalism. Emphasis is put on the fact that in non-equilibrium thermo field dynamics the change of a thermal situation due to an external source should appear through the thermal Bogoliubov transformation, creating a new contribution to the linear response formula. It is also found that the dissipativity naturally comes out in the conventional retarded correlation.
AB - The linear response theory is discussed in the context of non-equilibrium thermo field dynamics which has been developed in recent years and can deal with a quantum field system in time-dependent non-equilibrium situations. An example of a simple model is given to illustrate the present formalism. Emphasis is put on the fact that in non-equilibrium thermo field dynamics the change of a thermal situation due to an external source should appear through the thermal Bogoliubov transformation, creating a new contribution to the linear response formula. It is also found that the dissipativity naturally comes out in the conventional retarded correlation.
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U2 - 10.1016/0378-4371(88)90064-7
DO - 10.1016/0378-4371(88)90064-7
M3 - Article
AN - SCOPUS:45549119720
SN - 0378-4371
VL - 152
SP - 29
EP - 50
JO - Physica A: Statistical Mechanics and its Applications
JF - Physica A: Statistical Mechanics and its Applications
IS - 1-2
ER -