Closed-String Mirror Symmetry for Log Calabi-Yau Surfaces
Hyunbin Kim
TL;DR
The paper establishes closed-string mirror symmetry for all log Calabi-Yau surfaces with generic parameters, showing $ ext{Jac}(W)\\cong QH^{*}(X)$ where $W$ is the Landau-Ginzburg potential arising from SYZ mirror symmetry. It analyzes how blowups and, crucially, blowdowns of $(-1)$-divisors affect the critical locus of $W$, proving that each blowdown reduces the number of geometric critical points by exactly one and preserves Morse non-degeneracy. A key technical advance is the use of the star-shaped Newton polytope to accurately count geometric critical points and to track potential changes under blowdown, together with energy considerations of basic and broken disks. The authors then prove that $QH^{*}(X)$ is semisimple by linking distinct critical values of $W$ to eigenvalues of the quantum product by $c_{1}(X)$, solidifying closed-string mirror symmetry for this class and highlighting implications for the spectral theory of quantum cohomology in non-Fano settings.
Abstract
This paper establishes closed-string mirror symmetry for all log Calabi-Yau surfaces with generic parameters, where the exceptional divisor are sufficiently small. We demonstrate that blowing down a $(-1)$-divisor removes a single geometric critical point, ensuring that the resulting potential remains a Morse function. Additionally, we show that the critical values are distinct, which implies that the quantum cohomology $QH^{\ast}(X)$ is semi-simple.
