Looking for simple self energy calculations

[kaesekuchen86]

Hi everybody,

I'm writing my QFT exam tomorrow and I know that there will be a self energy calculation. Since I am not that familiar with it, because we didn't do any self energy calculations in the exercises so far, I would like to do some simple calculations.
I think the electron self energy, the vacuum polarization and the vertex correction are too difficult for an exam. I already found the easiest example for Phi^3 theory and I think something like this could come in the exam:

-----( )---------- (1 Bubble)


The calculation was not too difficult.
Do you guys know any other simple selfenergy calculation? I would like to be prepared as good as possible for tomorrow :)
Thank you!

 

[eljose79]

Hi there,

First of all, good luck on your QFT exam tomorrow! Self energy calculations can definitely be tricky, but with some practice and understanding of the concepts, you can definitely do well on the exam.

One simple self energy calculation that comes to mind is the calculation for the mass shift in a scalar field theory. This can be done by considering a scalar field interacting with a background scalar field, similar to the example you provided with the Phi^3 theory. Another simple example is the calculation for the self energy of a fermion in a Yukawa theory, which involves integrating over the momentum of the virtual particle.

In general, the key to self energy calculations is to carefully consider the Feynman diagrams involved and to use the appropriate Feynman rules. I would also recommend reviewing any notes or lectures on the topic and practicing with different examples to get a better understanding of the process.

Again, best of luck on your exam tomorrow! I hope this helps and please feel free to ask any other questions.