Mixed Hodge structures in log symplectic geometry

Abstract

We study the cohomology rings of snc log symplectic pairs $(X,Y)$ which have log symplectic forms of pure weight. We show that under a certain natural condition, the cohomology ring of $X\setminus Y$ exhibits the curious hard Lefschetz property. Analogous results are shown to hold for limit mixed Hodge structures associated to good degenerations of projective irreducible holomorphic symplectic manifolds. We provide several examples of log symplectic pairs of pure weight including a class of cluster-type varieties, and examples coming from the work of Feigin and Odesski. We show that the components of the central fiber of good degenerations of projective irreducible holomorphic symplectic manifolds produce log symplectic pairs.

arXiv comment34 pages. Comments welcome!

References in corpus (6)

• Poisson modules and degeneracy loci
• Cell decompositions of character varieties
• Elliptic singularities on log symplectic manifolds and Feigin--Odesskii Poisson brackets
• The LLV decomposition of hyper-Kaehler cohomology
• A characterization of diagonal Poisson structures
• P=W for Lagrangian fibrations and degenerations of hyper-Kähler manifolds

Cited by in corpus (1)

• A local Torelli theorem for log symplectic manifolds