# Time ordering operator, interaction Lagrangian, QED

## Homework Statement

I am trying to calculate the following quantity:
$$<0|T\{\phi^\dagger(x_1) \phi(x_2) exp[i\int{L_1(x)dx}]\}|0>$$

where:

$$L_1(x) = -ieA_{\mu}[\phi^* (\partial_\mu \phi ) - (\partial_\mu \phi^*)\phi]$$[/B]

I am trying to find an expression including the propagators, wick's theorem, and then calculate the Feynman diagrams in position space.
The solution should include terms of up to ## e^2 ## order.

## The Attempt at a Solution

I am not sure if the Lagrangian ## L_1(x) ## is the interaction Lagrangian, so that I should use it as it is in the integral, or if I should extract an interaction Lagrangian out of it.
I also have to tell you that I am not expected to calculate complex integrals in every detail, or be occupied with infinities.
[/B]

Related Advanced Physics Homework Help News on Phys.org
Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

DEvens