Groupes de renormalisation pour deux alg\`ebres de Hopf en produit   semi-direct
  We consider two interacting connected graded Hopf algebras, the former being a comodule-coalgebra on the latter. We show how to define analogues of Connes-Kreimer's renormalization group and Beta function, when the graduation operator is replaced by any biderivation coming from an infinitesimal character of the second Hopf algebra. 
Mohamed Belhaj Mohamed
math-ph math.MP