English

A Lagrangian sphere which is not a vanishing cycle

Symplectic Geometry 2019-06-17 v3 Algebraic Geometry

Abstract

We give examples of Calabi-Yau threefolds containing Lagrangian spheres which are not vanishing cycles of nodal degenerations, answering a question of Donaldson in the negative.

Keywords

Cite

@article{arxiv.1812.00489,
  title  = {A Lagrangian sphere which is not a vanishing cycle},
  author = {François Greer},
  journal= {arXiv preprint arXiv:1812.00489},
  year   = {2019}
}

Comments

8 pages, 1 figure. More details are included in the discussion after Prop. 5 and the proof of Prop. 8. Section 4 is streamlined significantly

R2 v1 2026-06-23T06:28:35.998Z