The PostLie algebra is an enriched structure of the Lie algebra that has
recently arisen from operadic study. It is closely related to pre-Lie algebra,
Rota-Baxter algebra, dendriform trialgebra, modified classical Yang-Baxter
equations and integrable systems. We give a complete classification of PostLie
algebra structures on the Lie algebra sl(2,C) up to isomorphism. We first
reduce the classification problem to solving an equation of 3 x 3 matrices.
This paper provides a general operadic definition for the notion of splitting
the operations of algebraic structures. This construction is proved to be
equivalent to some Manin products of operads and it is shown to be closely
related to Rota-Baxter operators. Hence, it gives a new effective way to
compute Manin black products. The present construction is shown to have
symmetry properties.
We generalize the well-known construction of dendriform dialgebras and
trialgebras from Rota-Baxter algebras to a construction from O-operators. We
then show that this construction from O-operators gives all dendriform
dialgebras and trialgebras. Furthermore there are bijections between certain
equivalence classes of invertible O-operators and certain equivalence classes
of dendriform dialgebras and trialgebras.
We generalize the classical study of (generalized) Lax pairs and the related
$O$-operators and the (modified) classical Yang-Baxter equation by introducing
the concepts of nonabelian generalized Lax pairs, extended $\calo$-operators
and the extended classical Yang-Baxter equation. We study in this context the
nonabelian generalized $r$-matrix ansatz and the related double Lie algebra
structures. Relationship between extended $O$-operators and the extended
classical Yang-Baxter equation is established, especially for self-dual Lie
algebras.
We introduce the concept of an extended O-operator that generalizes the
well-known concept of a Rota-Baxter operator. We study the associative products
coming from these operators and establish the relationship between extended
O-operators and the associative Yang-Baxter equation, extended associative
Yang-Baxter equation and generalized Yang-Baxter equation.