Recursive graphical construction of Feynman diagrams in quantum electrodynamics - art. no. 085017

We present a method for a recursive graphical construction of Feynman diagr ams with their correct multiplicities in quantum electrodynamics. The metho d is first applied to find all diagrams contributing to the vacuum energy f rom which all n-point functions are derived by functional differentiation w ith respect to electron and photon propagators, and to the interaction. The basis for our construction is a functional differential equation obeyed by the vacuum energy when considered as a functional of the free propagators and the interaction. Our method does not employ external sources in contras t with traditional approaches.