Many-body Green’s Functions Exercise (15) Solution: 10 second order diagrams for the Green’s function

Equation of Motion for the Green’s Function Exercise (16) Solution: 10 second order diagrams for the Green’s function To obtain self energy, cut off Go at either end to leave stubs There are six proper self-energy diagrams at second order

Evaluation of the Single Loop Bubble Exercise (17) Solution: Same result by closing the contour in the lower half plane

Evaluation of the Single Loop Bubble Exercise (18) Solution: continued For x y