English

Exotic Lagrangian tori in Grassmannians

Symplectic Geometry 2023-08-08 v2 Geometric Topology

Abstract

We describe an iterative construction of Lagrangian tori in the complex Grassmannian Gr(k,n)\operatorname{Gr}(k,n), based on the cluster algebra structure of the coordinate ring of a mirror Landau-Ginzburg model proposed by Marsh-Rietsch. Each torus comes with a Laurent polynomial, and local systems controlled by the kk-variables Schur polynomials at the nn-th roots of unity. We use this data to give examples of monotone Lagrangian tori that are neither displaceable nor Hamiltonian isotopic to each other, and that support nonzero objects in different summands of the spectral decomposition of the Fukaya category over C\mathbb{C}.

Keywords

Cite

@article{arxiv.1910.10888,
  title  = {Exotic Lagrangian tori in Grassmannians},
  author = {Marco Castronovo},
  journal= {arXiv preprint arXiv:1910.10888},
  year   = {2023}
}

Comments

26 pages, 5 figures. Simplified exposition; expanded discussion of generation of the Fukaya category