Timeline for What do the poles of a Green function mean, physically?
Current License: CC BY-SA 3.0
3 events
| when toggle format | what | by | license | comment | |
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| Aug 13, 2013 at 3:07 | comment | added | thone | The picture is similar. For free case without interaction, GF is real. For intacting case, there is a imaginary part which is related to self energy. Linear response is some kinds of interacting. | |
| Aug 12, 2013 at 15:22 | comment | added | user27777 | For classical linear response the GF can be neither purely real nor purely imaginary on any finite interval because of Kramers-Kronig. I.e., a real GF violates causality except in vacuum. Is this not true in QM? | |
| Jun 5, 2012 at 10:24 | history | answered | thone | CC BY-SA 3.0 |