Draw graphs for self-energy and Vertex functions

In summary, the conversation is about drawing graphs for self-energy and vertex functions, with one attachment containing the self-energy in coordinate space and a question about its expression in terms of the fermion propagator. The speaker is seeking help and feedback on their understanding and attachments. They also mention re-uploading the attachments.
  • #1
Neitrino
137
0
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
 
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  • #2
Any feedback please...
Or did I write something wrongly or incompletely?
 
  • #3
Not that I'd be able to help with the question, anyway... but I don't see any attachments.
 
  • #4
Graphs

Re-uploading the attachemnts.
 

Attachments

  • 1.pdf
    11.9 KB · Views: 2,428
  • 2.pdf
    15.5 KB · Views: 622

1. What is the purpose of drawing graphs for self-energy and vertex functions?

The purpose of drawing graphs for self-energy and vertex functions is to visually represent the mathematical calculations and relationships between different particles and their interactions in a quantum field theory. These graphs help to simplify complex equations and make it easier to understand the behavior of particles in different situations.

2. How are self-energy and vertex functions related?

Self-energy and vertex functions are both important components in the calculation of Feynman diagrams, which represent the interactions between particles in a quantum field theory. Self-energy is the correction to the mass and energy of a particle due to its interactions with other particles, while vertex functions describe the strength of these interactions.

3. What do the lines and vertices in the graphs represent?

The lines in the graphs represent the particles involved in the interaction, while the vertices represent the points where these particles interact. The number of lines connected to a vertex represents the number of particles involved in that particular interaction.

4. How do you interpret the direction of the lines in the graphs?

In Feynman diagrams, the direction of the lines represents the flow of time. Lines pointing to the right represent particles moving forward in time, while lines pointing to the left represent antiparticles moving backward in time.

5. Can these graphs be used to make predictions about particle behavior?

Yes, these graphs can be used to make predictions about particle behavior in different situations. By analyzing the interactions between particles and their corresponding self-energy and vertex functions, scientists can make predictions about the likelihood of certain particle interactions and the overall behavior of a system.

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