Published October 7, 2022 | Version v1
Publication

Shifted substitution in non-commutative multivariate power series with a view toward free probability

Description

We study a particular group law on formal power series in non-commuting variables induced by their interpretation as linear forms on a suitable graded connected word Hopf algebra. This group law is left-linear and is therefore associated to a pre-Lie structure on formal power series. We study these structures and show how they can be used to recast in a group theoretic form various identities and transformations on formal power series that have been central in the context of non-commutative probability theory, in particular in Voiculescu's theory of free probability.

Additional details

Created:
December 4, 2022
Modified:
November 29, 2023