Open WDVV Equations and Frobenius Structures for Toric Calabi-Yau 3-Folds
Song Yu, Zhengyu Zong
TL;DR
The paper develops open WDVV theory for toric Calabi-Yau 3-folds with Aganagic-Vafa branes by leveraging an open/closed correspondence with a toric Calabi-Yau 4-fold. It constructs two parallel formalisms: a semi-simple formal Frobenius manifold encoding open and closed Gromov-Witten data and a flat formal $F$-manifold capturing the same data in a different algebraic framework, including a nilpotent open direction. The approach hinges on relating $F_0^{X,T'}$ and $F_{0,1}^{X,(L,f)}$ to the genus-zero potential of the CY 4-fold $\widetilde{X}$ and proving corresponding open WDVV equations. Together, these results provide a structured, recursive, and algebraically robust way to organize and compute open and closed GW invariants in this toric geometric setting, with potential connections to variations of Hodge structures and open-closed maps.
Abstract
Let $X$ be a toric Calabi-Yau 3-fold and let $L\subset X$ be an Aganagic-Vafa outer brane. We prove two versions of open WDVV equations for the open Gromov-Witten theory of $(X,L)$. The first version of the open WDVV equation leads to the construction of a semi-simple (formal) Frobenius manifold and the second version leads to the construction of a flat (formal) $F$-manifold.
