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Draw graphs for self-energy and Vertex functions

  1. Nov 30, 2005 #1
    Could anyone help/advise me please how to draw graphs for self-energy and Vertex functions given in attachments one and two.
    In attachment one Sigma is self energy in coordinate space, S - fermion propagator, here I have one question: I was reading something where I found these exppresions, but how it can be that self-energy in attachment one is expressed only in terms of Propagator S(0), it's a just a vacuum bubble, just circle isn't it?

    Irealy need someones help.
    Thks a lot
  2. jcsd
  3. Dec 1, 2005 #2
    Any feedback please....
    Or did I write something wrongly or incompletely?
  4. Dec 1, 2005 #3


    User Avatar

    Staff: Mentor

    Not that I'd be able to help with the question, anyway... but I don't see any attachments.
  5. Dec 1, 2005 #4

    Re-uploading the attachemnts.

    Attached Files:

    • 1.pdf
      File size:
      11.9 KB
    • 2.pdf
      File size:
      15.5 KB
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