English

Chow cohomology and Lefschetz (1,1)-theorem

Algebraic Geometry 2025-06-17 v1

Abstract

Any smooth, projective variety satisfies the Hodge conjecture in codimension one, known as the Lefschetz (1,1) theorem. Totaro formulated a version for singular varieties. He asked whether the natural Bloch-Gillet-Soul\'{e} cycle class map from the operational Chow group to the (1,1)-classes in the weight graded piece of the cohomology group is surjective? In this short article, we give a sufficient criterion for this to hold. In particular, we show that several singular varieties with at worst isolated singularities (log canonical, divisorial log terminal, ADE-singularities) satisfy the singular Hodge conjecture in codimension 1.

Keywords

Cite

@article{arxiv.2506.13220,
  title  = {Chow cohomology and Lefschetz (1,1)-theorem},
  author = {Ananyo Dan and Inder Kaur},
  journal= {arXiv preprint arXiv:2506.13220},
  year   = {2025}
}

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11 pages