@article{SLC_2017_78B_a57,
author = {Matthieu Josuat-Verg\`es and Fr\'ed\'eric Menous and Jean-Christophe Novelli and Jean-Yves Thibon},
title = {Noncommutative {Free} {Cumulants}},
journal = {S\'eminaire lotharingien de combinatoire},
year = {2017},
volume = {78B},
url = {http://geodesic.mathdoc.fr/item/SLC_2017_78B_a57/}
}
TY - JOUR
AU - Matthieu Josuat-Vergès
AU - Frédéric Menous
AU - Jean-Christophe Novelli
AU - Jean-Yves Thibon
TI - Noncommutative Free Cumulants
JO - Séminaire lotharingien de combinatoire
PY - 2017
VL - 78B
UR - http://geodesic.mathdoc.fr/item/SLC_2017_78B_a57/
ID - SLC_2017_78B_a57
ER -
The relation between moments and free cumulants in free probability is essentially a compositional inversion. We lift it at the level of the noncommutative Faà di Bruno algebra, and of an operad of Schröder trees. We get a new formula for free cumulants in terms of trees, and we recover an interpretation of the relation in terms of characters due to Ebrahimi-Fard and Patras.