English

Counting curves via degeneration

Algebraic Geometry 2015-10-08 v3 Symplectic Geometry

Abstract

We develop a technique to study curves in a variety which has a degeneration into some union of varieties. The class of such varieties is very broad, but the theory becomes particularly useful when the variety has a degeneration into a union of toric varieties. Hypersurfaces are typical examples, and we study lines on K3 surfaces and quintic Calabi-Yau hypersurfaces in detail. In particular, we combinatorially prove the existence of 2875 lines in a generic quintic Calabi-Yau 3-fold. Also, we give a geometric construction of walls in the Gross-Siebert construction of Calabi-Yau varieties.

Keywords

Cite

@article{arxiv.1108.2802,
  title  = {Counting curves via degeneration},
  author = {Takeo Nishinou},
  journal= {arXiv preprint arXiv:1108.2802},
  year   = {2015}
}

Comments

v2. Added references

R2 v1 2026-06-21T18:50:09.815Z