Rooted trees, non-rooted trees and hamiltonian B-series

Abstract

We explore the relationship between (non-planar) rooted trees and free trees, i.e. without root. We give in particular, for non-rooted trees, a substitute for the Lie bracket given by the antisymmetrization of the pre-Lie product.

8 pages, axodraw used for drawing trees

References in corpus (1)

• Relating two Hopf algebras built from an operad