Feynman Diagrams and Lax Pair Equations
arXiv:0905.2271
Abstract
We find a Lax pair equation corresponding to the Connes-Kreimer Birkhoff factorization of the character group of a Hopf algebra. This flow preserves the locality of counterterms. In particular, we obtain a flow for the character given by Feynman rules, and relate this flow to the Renormalization Group Flow.
Rewritten and expanded version of math-ph/0611014