Interactions as conformal intertwiners in 4D QFT

Understand

In a recent paper we showed that the correlators of free scalar field theory in four dimensions can be constructed from a two dimensional topological field theory based on so(4,2) equivariant maps (intertwiners).

• The free field result, along with results of Frenkel and Libine on equivariance properties of Feynman integrals, are developed further in this paper.
• We show that the coefficient of the log term in the 1-loop 4-point conformal integral is a projector in the tensor product of so(4,2) representations.
• We also show that the 1-loop 4-point integral can be written as a sum of four terms, each associated with the quantum equation of motion for one of the four external legs.