Counter-terms
Michel Talagrand · Cambridge University Press eBooks · 2022
The physicist’s counter-term method enriches the class of possible diagrams by adding new types of vertices. We explain in simple cases how this method can be used to re-parameterize a theory, and how the physicists use it to tame the diverging integrals by having “the counter terms cancel the divergences”. Assuming that the BPHZ method succeeds in producing finite results for the scattering amplitudes, we prove that the counter-term method succeeds too.