# Homework Help: [QFT] Divergent Green's function?

1. Mar 6, 2010

### nocloud

1. The problem statement, all variables and given/known data

I am being asked to consider a Dirac spinor with two complex components and the following Lagrangian:

$$L = L_{Dirac}-\stackrel{g}{4}{(\psi\bar{\psi})^{2}}$$

I am asked to derive the Feynman rules for this theory which I can do using the standard methods. However, I am also asked to "classify the divergent Green's functions". Can anybody tell me what this question wants me to do? I am drawing a bit of blank here and googling "divergent Green's functions" isn't leading to a whole lot of useful information.

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution