ABSTRACT
In this chapter, the LSZ reduction formulae introduced in Chapter 7 are employed to obtain the explicit expression of the S-matrix elements in the https://www.w3.org/1998/Math/MathML" display="inline"> λ ϕ 4 theory from the perturbative expansion of the Green's functions derived in Chapter 8. The classification of diagrams according to their topological structure, leading to the identification of one-particle-irreducible diagrams is discussed. The ensuing Feynman rules are outlined, and the explicit expression of the basic diagrammatic elements are provided.
