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Hopf algebras and dendriform structures arising from parking functions

Jean-Christophe Novelli, Jean-Yves Thibon (2007)

Fundamenta Mathematicae

We introduce a graded Hopf algebra based on the set of parking functions (hence of dimension ( n + 1 ) n - 1 in degree n). This algebra can be embedded into a noncommutative polynomial algebra in infinitely many variables. We determine its structure, and show that it admits natural quotients and subalgebras whose graded components have dimensions respectively given by the Schröder numbers (plane trees), the Catalan numbers, and powers of 3. These smaller algebras are always bialgebras and belong to some family...

Jucys-Murphy elements and the unitary Weingarten function

Jonathan I. Novak (2010)

Banach Center Publications

We describe an approach to the unitary Weingarten function based on the JM elements of symmetric group algebras. When combined with previously known properties of the Weingarten function, this gives a surprising connection with the Moebius function of the lattice of noncrossing partitions.

Le module dendriforme sur le groupe cyclique

Frédéric Chapoton (2008)

Annales de l’institut Fourier

La structure d’opérade anticyclique de l’opérade dendriforme donne en particulier une matrice d’ordre n agissant sur l’espace engendré par les arbres binaires plans à n feuilles. On calcule le polynôme caractéristique de cette matrice. On propose aussi une conjecture compatible pour le polynôme caractéristique de la transformation de Coxeter du poset de Tamari, qui est essentiellement une racine carrée de cette matrice.

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