Local exotic tori

Abstract

For a broad class of symplectic manifolds of dimension at least six, we find the following new phenomenon: there exist local exotic Lagrangian tori. More specifically, let $X$ be a geometrically bounded symplectic manifold of dimension at least six. We show that every open subset of $X$ contains infinitely many Lagrangian tori which are distinct up to symplectomorphisms of $X$ while being Lagrangian isotopic and having the same classical invariants. The proof relies on a locality property of the displacement energy germ, which allows us to compute it in a Darboux chart. Since these tori are not monotone, bubbling may occur and the count of Maslov index two $J$-holomorphic disks does not yield an invariant.