Mirror symmetry and Fukaya categories of singular hypersurfaces
Maxim Jeffs
TL;DR
This work provides a principled A-model construction for the Fukaya category of singular hypersurfaces by localizing the Fukaya category of nearby fibers at Seidel's natural transformation, and proves an A-model analog of Orlov's Knörrer periodicity: for a smooth affine $X$ and a polynomial $f$ with a single critical fiber, $D^{\pi}\mathcal{W}(f^{-1}(0))$ is equivalent to $D^{\pi}\mathcal{W}(X\times\mathbb{C},zf)$ after inverting $s$. The authors establish an upgraded Abouzaid–Auroux–Katzarkov equivalence between $\mathcal{W}(f^{-1}(t))$ and $\mathcal{W}(X\times\mathbb{C},z(f-t))$, extend it to relative/fiberwise-stop contexts, and then deduce the Knörrer-type equivalence via stop-removal and generation, yielding HMS-type statements at large complex structure limits for abelian varieties. The paper also demonstrates concrete mirror-symmetry consequences, including the Tower of Pants, nodal curves, and elliptic curves, and discusses generalizations in the Gross–Siebert program linking large complex/volume limits through the family Floer framework. Overall, it provides a robust bridge between singular symplectic geometry, LG models, and mirror symmetry, with potential extensions to complete intersections and logarithmic structures.
Abstract
We consider a definition of the Fukaya category of a singular hypersurface proposed by Auroux, given by localizing the Fukaya category of a nearby fiber at Seidel's natural transformation, and show that this possesses several desirable properties. Firstly, we prove an A-side analog of Orlov's derived Knörrer periodicity theorem by showing that Auroux's category is derived equivalent to the Fukaya-Seidel category of a higher-dimensional Landau-Ginzburg model. Secondly, we describe how this definition implies homological mirror symmetry for some large complex structure limit degenerations of abelian varieties.
