English

A comodule-bialgebra structure for word-series substitution and mould composition

Combinatorics 2017-09-08 v2 Quantum Algebra

Abstract

An internal coproduct is described, which is compatible with Hoffman's quasi-shuffle product. Hoffman's quasi-shuffle Hopf algebra, with deconcatenation coproduct, is a comodule-Hopf algebra over the bialgebra thus defined. The relation with J. Ecalle's mould calculus, i.e. mould composition and contracting arborification, is precised.

Keywords

Cite

@article{arxiv.1609.03549,
  title  = {A comodule-bialgebra structure for word-series substitution and mould composition},
  author = {Kurusch Ebrahimi-Fard and Frédéric Fauvet and Dominique Manchon},
  journal= {arXiv preprint arXiv:1609.03549},
  year   = {2017}
}

Comments

revised version, accepted for publication in Journal of Algebra

R2 v1 2026-06-22T15:47:33.627Z