Abstract
The development of the time-translation operators in a matrix element of an arbitrary operator is examined. It is noted that we may interpret time as evolving from some remotely early time (t0) to a time in the far future (t∝) and then back to (t0). Using this interpretation, a perturbation expansion is developed for Green's functions defined along this path and a separation of the two-particle interaction terms into self-energy parts and single-particle Green's function terms is justified for quantities on this path. A connection is established between the real-time Green's functions and the Green's function defined along the path, thereby yielding a perturbation expansion for the real-time functions and a justification of the separation of the interaction terms in the equations of motion for the real-time quantities. The transport equations of Kadanoff and Baym are derived without resorting to an analytic continuation from imaginary times and without the correction terms of Fujita.
References
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Dates
Type | When |
---|---|
Created | 21 years, 6 months ago (Feb. 10, 2004, 12:14 p.m.) |
Deposited | 1 year, 6 months ago (Feb. 10, 2024, 11:05 p.m.) |
Indexed | 1 month, 3 weeks ago (July 2, 2025, 3:27 p.m.) |
Issued | 57 years, 4 months ago (April 1, 1968) |
Published | 57 years, 4 months ago (April 1, 1968) |
Published Print | 57 years, 4 months ago (April 1, 1968) |
@article{Craig_1968, title={Perturbation Expansion for Real-Time Green’s Functions}, volume={9}, ISSN={1089-7658}, url={http://dx.doi.org/10.1063/1.1664616}, DOI={10.1063/1.1664616}, number={4}, journal={Journal of Mathematical Physics}, publisher={AIP Publishing}, author={Craig, R. A.}, year={1968}, month=apr, pages={605–611} }