Lie Admissible Triple Algebras: The Connection Algebra of Symmetric Spaces

TL;DR

This paper introduces Lie admissible triple algebras as a new algebraic structure arising from symmetric spaces with canonical connections, generalizing pre-Lie and Lie triple systems, and describes their free algebra construction.

Contribution

It defines Lie admissible triple algebras, explores their properties, and shows how they embed into post-Lie algebras, extending the algebraic framework of symmetric spaces.

Findings

Lie admissible triple algebra generalizes pre-Lie algebras

Canonical embedding into post-Lie algebras established

Free Lie admissible triple algebra described using rooted trees

Abstract

Associated to a symmetric space there is a canonical connection with zero torsion and parallel curvature. This connection acts as a binary operator on the vector space of smooth sections of the tangent bundle, and it is linear with respect to the real numbers. Thus the smooth section of the tangent bundle together with the connection form an algebra we call the connection algebra. The constraints of zero torsion and constant curvature makes the connection algebra into a Lie admissible triple algebra. This is a type of algebra that generalises pre-Lie algebras, and it can be embedded into a post-Lie algebra in a canonical way that generalises the canonical embedding of Lie triple systems into Lie algebras. The free Lie admissible triple algebra can be described by incorporating triple-brackets into the leaves of rooted (non-planar) trees.