Wave-Function renormalization and the Hopf algebra of Connes and Kreimer

Abstract

In this talk, we show how the Connes-Kreimer Hopf algebra morphism can be extended when taking into account the wave-function renormalization. This leads us to a semi-direct product of invertible power series by formal diffeomorphisms.Comment: 5 pages, no figure, talk presented in the conference "Brane New World and Noncommutative Geometry", Torino, Villa Gualino,(Italy) Octobe