On the Signature of a Path in an Operator Algebra

We introduce a class of operators associated with the signature of a smooth path 𝑋 with values in a 𝐶⋆ algebra 𝒜. These operators serve as the basis of Taylor expansions of solutions to controlled differential equations of interest in noncommutative probability. They are defined by fully contracting...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Symmetry, Integrability and Geometry: Methods and Applications
Datum:2022
Hauptverfasser: Gilliers, Nicolas, Bellingeri, Carlo
Format: Artikel
Sprache:Englisch
Veröffentlicht: Інститут математики НАН України 2022
Online Zugang:https://nasplib.isofts.kiev.ua/handle/123456789/211808
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Zitieren:On the Signature of a Path in an Operator Algebra. Nicolas Gilliers and Carlo Bellingeri. SIGMA 18 (2022), 096, 43 pages

Institution

Digital Library of Periodicals of National Academy of Sciences of Ukraine
Beschreibung
Zusammenfassung:We introduce a class of operators associated with the signature of a smooth path 𝑋 with values in a 𝐶⋆ algebra 𝒜. These operators serve as the basis of Taylor expansions of solutions to controlled differential equations of interest in noncommutative probability. They are defined by fully contracting iterated integrals of 𝑋, seen as tensors, with the product of 𝒜. If it is considered that partial contractions should be included, we explain how these operators yield a trajectory on a group of representations of a combinatorial Hopf monoid. To clarify the role of partial contractions, we build an alternative group-valued trajectory whose increments embody full-contraction operators alone. We obtain, therefore, a notion of signature, which seems more appropriate for noncommutative probability.
ISSN:1815-0659