Cusped hyperbolic Lagrangians as mirrors to lines in three-space

Abstract

We construct a Lagrangian in the cotangent bundle of a 3-torus whose projection to the fiber is a neighborhood of a tropical curve with a single 4-valent vertex. This Lagrangian has an isolated conical singular point, and its smooth locus is diffeomorphic to the minimally-twisted five component chain link complement, a cusped hyperbolic 3-manifold. From this singular Lagrangian, we construct an immersed Lagrangian, and determine when it is unobstructed in the wrapped Fukaya category. We show that for a generic line in projective 3-space, there is a local system on this immersed Lagrangian such that the resulting object of the wrapped Fukaya category is homologically mirror to an object of the derived category supported on the line. In the course of the proof, we construct a version of the wrapped Fukaya category with objects supported on Lagrangian immersions, which may be of independent interest.