Conifold Gap for the Quintic Threefold

Abstract

We prove the all-genus conifold gap conjecture for the Gromov--Witten (GW) theories of the quintic threefold, other smooth Fermat Calabi--Yau threefold hypersurfaces, and local ${\mathbb{P}}^2$, as well as for the FJRW theories associated with these hypersurfaces. Our proof uses Mixed Spin P-field (MSP) theory and analogous master-space constructions. The central object is the \emph{cone-vertex theory}. We express this theory as a translation of the point CohFT via a formal Laplace transform and prove a universal conifold gap theorem for the resulting translated theories. The master-space construction then transfers the gap from the cone-vertex theory to the GW and FJRW theories.