Nijenhuis operators and twisted $\mathcal{O}$-operators on Nambu-Poisson algebras
Apurba Das, Fattoum Harrathi, Sami Mabrouk
TL;DR
The paper extends the theory of Nijenhuis operators, NS-algebras, and twisted $\mathcal{O}$-operators to Nambu-Poisson algebras of order $3$, developing a second cohomology framework that combines Harrison cohomology with $3$-Lie cohomology. It studies $(1,2)$-linear deformations and proves that trivial deformations yield Nijenhuis operators, which in turn generate deformed Nambu-Poisson structures; to understand these deformations, it introduces NS-Nambu-Poisson algebras that split the NP structure. Twisted $\mathcal{O}$-operators are defined in this context and shown to encode NS-Nambu-Poisson structures via their graphs, with the induced representation carrying a natural NP structure. The work also clarifies the relationship between NS-Nambu-Poisson algebras and the subadjacent NP algebras, and identifies Reynolds operators as a specialized twisted Rota-Baxter case, linking these constructions to broader deformation and bialgebra theories. These results lay groundwork for further study of NP cohomology, NP deformations, and potential NP bialgebra formalisms, including post-NP and matched-pair constructions.
Abstract
A ternary Nambu-Poisson algebra (which we call a Nambu-Poisson algebra in the paper) is the underlying algebraic structure of Nambu-Poisson manifolds of order $3$ that appeared in the generalized Hamiltonian mechanics. First, we consider the 2nd cohomology group of a Nambu-Poisson algebra with coefficients in a given representation. Next, we discuss suitable linear deformations of a Nambu-Poisson algebra and show that any such trivial deformation yields a Nijenhuis operator on it. To understand the deformed Nambu-Poisson algebra obtained from a Nijenhuis operator, we introduce a new algebraic structure, which we name NS-Nambu-Poisson algebras. Finally, we consider $\mathcal{O}$-operators twisted by $2$-cocycles and find their close relationships with NS-Nambu-Poisson algebras.
