English

Hyperelliptic classes are rigid and extremal in genus two

Algebraic Geometry 2024-02-28 v5

Abstract

We show that the class of the locus of hyperelliptic curves with \ell marked Weierstrass points, mm marked conjugate pairs of points, and nn free marked points is rigid and extremal in the cone of effective codimension-(+m\ell + m) classes on M2,+2m+n\overline{\mathcal{M}}_{2,\ell+2m+n}. This generalizes work of Chen and Tarasca and establishes an infinite family of rigid and extremal classes in arbitrarily-high codimension.

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Cite

@article{arxiv.1707.08676,
  title  = {Hyperelliptic classes are rigid and extremal in genus two},
  author = {Vance Blankers},
  journal= {arXiv preprint arXiv:1707.08676},
  year   = {2024}
}

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Published version

R2 v1 2026-06-22T20:58:41.537Z