Extremal Lagrangian tori in toric domains
Abstract
Let be a closed Lagrangian submanifold of a symplectic manifold . Cieliebak and Mohnke define the symplectic area of as the minimal positive symplectic area of a smooth -disk in with boundary on . An extremal Lagrangian torus in is a Lagrangian torus that maximizes the symplectic area among the Lagrangian tori in . We prove that every extremal Lagrangian torus in the symplectic unit ball is contained entirely in the boundary . This answers a question attributed to Lazzarini and completely settles a conjecture of Cieliebak and Mohnke in the affirmative. In addition, we prove the conjecture for a class of toric domains in , which includes all compact strictly convex four-dimensional toric domains. We explain with counterexamples that the general conjecture does not hold for non-convex domains.
Cite
@article{arxiv.2504.13076,
title = {Extremal Lagrangian tori in toric domains},
author = {Shah Faisal},
journal= {arXiv preprint arXiv:2504.13076},
year = {2026}
}
Comments
93 pages, 12 figures. Revised version incorporating the referee's suggestions and comments