English

Tropically constructed Lagrangians in mirror quintic threefolds

Symplectic Geometry 2020-11-25 v3 Algebraic Geometry Differential Geometry

Abstract

We use tropical curves and toric degeneration techniques to construct closed embedded Lagrangian rational homology spheres in a lot of Calabi-Yau threefolds. We apply this construction to the tropical curves obtained from the 2875 lines on the quintic Calabi-Yau threefold. Each admissible tropical curve gives a Lagrangian rational homology sphere in the corresponding mirror quintic threefold and disjoint curves give pairwise homologous but non-Hamiltonian isotopic Lagrangians. We check in an example that >300>300 mutually disjoint curves (and hence Lagrangians) arise. We show that the weight of each of these Lagrangians equals to the multiplicity of the corresponding tropical curve.

Keywords

Cite

@article{arxiv.1904.11780,
  title  = {Tropically constructed Lagrangians in mirror quintic threefolds},
  author = {Cheuk Yu Mak and Helge Ruddat},
  journal= {arXiv preprint arXiv:1904.11780},
  year   = {2020}
}

Comments

75 pages, 13 figures, final version, to appear in Forum Math. Sigma, ancillary files with source code and documentation added

R2 v1 2026-06-23T08:50:20.030Z