Learn More
We give a natural and complete description of Ecalle's mould–comould formalism within a Hopf–algebraic framework. The arborification transform thus appears as a factorization of characters, involving the shuffle or quasishuffle Hopf algebras, thanks to a universal property satisfied by Connes–Kreimer Hopf algebra. We give a straightforward characterization(More)
We present algorithms which involve both the splitting of formal series solutions to linear ordinary differential equations with polynomial coefficients into a finite sum of subseries which themselves will be solutions of linear ODEs, and the simplification of the recurrence relations satisfied by their coefficients.When coping with series that are(More)
  • 1