Field Theory
        Georgia Tech PHYS-7147              spring 2005
        Tue, Thu 12:05-13:25                 Howey S107

				Homework Assignment #10
				-----------------------
				due Thu, Apr 7

QED Feynman rules
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1. write down the QED Lagrangian density
   use (1,-1,-1,-1) metric

2. derive the momentum space electron propagator
   from the free electron Lagrangian density

3. derive the momentum space photon propagator from 
   the free electromagnetic Maxwell action, in whatever
   gauge you like

4. derive the electron/positron-photon 3-vertex

5. write down explicitely the momentum-space integrals
   corresponding to the 1-loop correction to 1-P-I
   electron/positron-photon vertex

NOTE: make sure that all i's and relative signs are correct


Reading: 

   Field Theory book -  ChaosBook.org/FieldTheory
   Chapter 5, Sections B, C  
   Chapter 6, Sections A, B  

   whatever Field Theory book/notes if you feel
   unsure about what you get for exers. 1-5 above

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bits and pieces already done you might find useful:

				Homework Assignment #2
				----------------------
   B: the 4-vertex momentum in continuum limit

				Homework Assignment #3
				----------------------
   Exercise 2.D.1, 2.D.3, 2.E.2

				Homework Assignment #5
				----------------------
   Exercise 3.F.2, 3.F.3
				Homework Assignment #7
				----------------------
   Exercise 4.C.1

to get signs right, read:
ChaosBook.org/library
	A. Zee on attractive/repulsive particle exchanges