English

Components of the Hilbert Scheme of smooth projective curves using ruled surfaces

Algebraic Geometry 2020-03-17 v2

Abstract

Let Id,g,r\mathcal{I}_{d,g,r} be the union of irreducible components of the Hilbert scheme whose general points correspond to smooth irreducible non-degenerate curves of degree dd and genus gg in Pr\mathbb{P}^r. We use families of curves on cones to show that under certain numerical assumptions for dd, gg and rr, the scheme Id,g,r\mathcal{I}_{d,g,r} acquires generically smooth components whose general points correspond to curves that are double covers of irrational curves. In particular, in the case ρ(d,g,r):=g(r+1)(gd+r)0\rho(d,g,r) := g-(r+1)(g-d+r) \geq 0 we construct explicitly a regular component that is different from the distinguished component of Id,g,r\mathcal{I}_{d,g,r} dominating the moduli space Mg\mathcal{M}_g.

Keywords

Cite

@article{arxiv.1807.05137,
  title  = {Components of the Hilbert Scheme of smooth projective curves using ruled surfaces},
  author = {Youngook Choi and Hristo Iliev and Seonja Kim},
  journal= {arXiv preprint arXiv:1807.05137},
  year   = {2020}
}