A Lagrangian sphere which is not a vanishing cycle
arXiv:1812.00489
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.
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