Mirror symmetry for tropical hypersurfaces and patchworking
Diego Matessi, Arthur Renaudineau
TL;DR
This work develops a robust bridge between tropical mirror symmetry and patchworking by proving canonical isomorphisms between integral tropical homology groups of mirror tropical Calabi–Yau hypersurfaces. It introduces a detailed combinatorial framework that refines posets and defines a mirror cosheaf, yielding a rigorous mirror correspondence for tropical homology that recovers Hodge dualities in convex cases. The authors then connect these tropical constructions to real Calabi–Yau hypersurfaces obtained from primitive patchworking, deriving a precise criterion: under a tropical-homology vanishing hypothesis, the real patchworked hypersurface is connected if and only if the tropical divisor class on the mirror vanishes; otherwise it has at most two components. The results illuminate how real topological features of patchworked varieties are governed by combinatorial and tropical data on the mirror, with potential extensions to higher pages of the patchworking spectral sequence and to non-convex unimodular subdivisions.
Abstract
In the first part of the paper, we prove a mirror symmetry isomorphism between integral tropical homology groups of a pair of mirror tropical Calabi-Yau hypersurfaces. We then apply this isomorphism to prove that a primitive patchworking of a central triangulation of a reflexive polytope gives a connected real Calabi-Yau hypersurface if and only if the corresponding divisor class on the mirror is not zero.
