Deformation quantisation of exact shifted symplectic structures, with an application to vanishing cycles

TL;DR

This paper develops a comprehensive framework linking shifted symplectic and Poisson structures with deformation quantisation, applicable across various geometric contexts, and applies it to derive new insights into vanishing cycles and perverse sheaves.

Contribution

It generalizes the correspondence between shifted symplectic and Poisson structures to include formal derivations and applies this to quantisation and vanishing cycles in derived geometry.

Findings

Established a correspondence between exact shifted symplectic and non-degenerate shifted Poisson structures with formal derivation.

Proved the existence of unique self-dual deformation quantisations for these structures.

Connected the quantisation of complex (-1)-shifted symplectic structures to perverse sheaves of vanishing cycles.

Abstract

We extend the author's and CPTVV's correspondence between shifted symplectic and Poisson structures to establish a correspondence between exact shifted symplectic structures and non-degenerate shifted Poisson structures with formal derivation, a concept generalising constructions by De Wilde and Lecomte. Our formulation is sufficiently general to encompass derived algebraic, analytic and $\mathcal{C}^{\infty}$ stacks, as well as Lagrangians and non-commutative generalisations. We also show that non-degenerate shifted Poisson structures with formal derivation carry unique self-dual deformation quantisations in any setting where the latter can be formulated. One application is that for (not necessarily exact) $0$-shifted symplectic structures in analytic and $\mathcal{C}^{\infty}$ settings, it follows that the author's earlier parametrisations of quantisations are in fact independent of any choice of associator, and generalise Fedosov's parametrisation of quantisations for classical manifolds. Our main application is to complex $(-1)$-shifted symplectic structures, showing that our unique quantisation of the canonical exact structure, a sheaf of twisted $BD_0$-algebras with derivation, gives rise to BBDJS's perverse sheaf of vanishing cycles, equipped with its monodromy operator.