Shifted double Poisson structures and noncommutative Poisson extensions
Leilei Liu, Jieheng Zeng, Hu Zhao
TL;DR
The paper develops a comprehensive framework for shifted noncommutative Poisson geometry via double Poisson structures and their extensions, establishing that $n$-shifted double Poisson brackets on augmented dg algebras induce graded Lie structures on reduced cyclic homology and descend compatibly through noncommutative Hamiltonian reduction. It introduces the $\mathfrak{s}$-construction and a cobar–bar canonical resolution to transport double Poisson brackets to derived settings, proving independence of cofibrant resolutions and yielding a derived, homotopical perspective on NC Poisson structures. The Kontsevich–Rosenberg principle is extended to shifted, derived representation schemes, linking noncommutative data to shifted Poisson structures on derived moduli stacks of representations and their Cartan models. The work applies these developments to preprojective algebras, proving a canonical graded Lie algebra structure on the reduced cyclic homology of $\Pi Q$ and extending this structure along the cobar–bar construction to various deformations, with broader implications for quiver varieties and representation theory.
Abstract
We develop a theory of noncommutative Poisson extensions. For an augmented dg algebra \(A\), we show that any shifted double Poisson bracket on \(A\) induces a graded Lie algebra structure on the reduced cyclic homology. Under the Kontsevich--Rosenberg principle, we further prove that the noncommutative Poisson extension is compatible with noncommutative Hamiltonian reduction. Moreover, we show that shifted double Poisson structures are independent of the choice of cofibrant resolutions and that they induce shifted Poisson structures on the derived moduli stack of representations.
