Integration of the elliptic tangent bundle and elliptic Poisson structures
Bas Wensink
TL;DR
This work provides an explicit Lie groupoid integration for the elliptic tangent bundle $\mathcal{A}_{|D|}$ associated to (possibly non-coorientable) elliptic divisors $D$ on a manifold $M$, and establishes precise topological criteria for the existence of Hausdorff, $s$-connected integrations. It develops the integration in progressively general cases, from a smooth coorientable divisor via a complex blow-up, to coorientation coverings, non-coorientable cases, and finally normal-crossing divisors, using a mix of local blow-ups, double covers, and pushouts. The paper also constructs a canonical elliptic ideal on the resulting groupoids and provides local models for the symplectic integration of elliptic Poisson structures, including nonzero and zero elliptic residue cases, connecting with known holomorphic integrations. These results bridge the infinitesimal elliptic tangent geometry with explicit global groupoid models, enabling potential pseudodifferential calculus and symplectic integration in singular settings along codimension-two loci. The constructions yield concrete criteria and models with explicit isotropy and orbit structures, informing both the geometry of elliptic divisors and applications to elliptic Poisson/symplectic geometry.
Abstract
We explicitly construct a Lie groupoid integrating the elliptic tangent bundle associated to a (possibly normal crossing) elliptic divisor, providing a necessary and sufficient topological condition for the existence of a Hausdorff integration. We also produce an explicit local model for the symplectic integration of an elliptic Poisson structure.
