Divergences and Ambiguities in Renormalization Group Functions
Anders Eller Thomsen (University of Bern)

RG functions are used in QFT to evolve theories between energy scales and are frequently used in both phenomenology and theory. Starting at the 3-loop order, certain RG functions start exhibiting poles in the dimensional expansion, contrasting with the expectation that they should be finite. In this talk, I will clarify how this issue can be understood and how it is linked with an ambiguity in choosing renormalization constants that goes beyond a simple choice of renormalization scheme. The discussion will lead to a preferred prescription for the RG functions, which guarantees finiteness.