English

Unboundedness of zero-cycles on higher dimensional Fano manifolds

Algebraic Geometry 2025-12-02 v1 Number Theory

Abstract

We show that, unlike del Pezzo surfaces, higher dimensional Fano manifolds do not satisfy in general boundedness properties for their CH0{\rm CH}_0 group of 00-cycles. For example, for quartic threefolds having a point of odd degree, there is no ``Coray type" uperbound on the minimal odd degrees of points. Also, the CH0{\rm CH}_0-group of Fano hypersurfaces can be ``unbounded'' (a notion which is related to infinite dimensionality in the sense of Mumford), meaning that there is no integer NN such that 00-cycles of degree at least NN are effective.

Keywords

Cite

@article{arxiv.2511.23080,
  title  = {Unboundedness of zero-cycles on higher dimensional Fano manifolds},
  author = {Claire Voisin},
  journal= {arXiv preprint arXiv:2511.23080},
  year   = {2025}
}