Toric degenerations yielding Lagrangian torus fibrations with controlled singularities

Establish that toric degenerations of Calabi–Yau hypersurfaces and complete intersections admit Lagrangian torus fibrations whose singularities are modeled on a small, finite collection of singularity types, thereby confirming the long-standing conjectural picture underpinning the SYZ program.

Background

The authors highlight a foundational geometric input for the local-to-global SYZ reconstruction program: the existence of Lagrangian torus fibrations for toric degenerations of Calabi–Yau varieties with singularities drawn from a small list of model types. They note that, despite widespread expectations, this has not yet been satisfactorily established.

Confirming this conjecture would provide the requisite differential-geometric scaffolding to build involutive covers by Liouville domains and systematically apply the deformation-theoretic and Mayer–Vietoris tools developed in the paper, thereby enabling explicit mirror reconstructions in broad Calabi–Yau settings.

References

It has long been conjectured for example that a toric degeneration of Calabi-Yau hypersurfaces and complete intersections should give rise a Lagrangian torus fibration with singularities modeled on some small number of types of singularities. However, to the best of our knowledge this has not yet been established satisfactorily.

— Boundary Depth and Deformations of Symplectic Cohomology  (2510.17607 - Groman, 20 Oct 2025) in Subsection ‘The local to global method in Floer theory’ (\ref{subsec:local-global}), Remark in discussion