(Pure) Transcendence Bases in φ-Deformed Shuffle Bialgebras
Séminaire lotharingien de combinatoire, Tome 74 (2015-2018)
Citer cet article
Voir la notice de l'acte provenant de la source Séminaire Lotharingien de Combinatoire website
Computations with integro-differential operators are often carried out in an associative algebra with unit, and they are essentially non-commutative computations. By adjoining a cocommutative co-product, one can have those operators act on a bialgebra isomorphic to an enveloping algebra. This gives an adequate framework for a computer-algebra implementation via monoidal factorization, (pure) transcendence bases and Poincaré-Birkhoff-Witt bases.
In this paper, we systematically study these deformations, obtaining necessary and sufficient conditions for the operators to exist, and we give the most general cocommutative deformations of the shuffle co-product and an effective construction of pairs of bases in duality. The paper ends by the combinatorial setting of local systems of coordinates on the group of group-like series.