English

Hodge sheaves underlying flat projective families

Algebraic Geometry 2023-02-13 v3

Abstract

We show that, for any fixed weight, there is a natural system of Hodge sheaves, whose Higgs field has no poles, arising from a flat projective family of varieties parametrized by a regular complex base scheme, extending the analogous classical result for smooth projective families due to Griffiths. As an application, based on positivity of direct image sheaves, we establish a criterion for base spaces of rational Gorenstein families to be of general type. A key component of our arguments is centered around the construction of derived categorical objects generalizing relative logarithmic forms for smooth maps and their functorial properties.

Keywords

Cite

@article{arxiv.2103.03515,
  title  = {Hodge sheaves underlying flat projective families},
  author = {Sándor J. Kovács and Behrouz Taji},
  journal= {arXiv preprint arXiv:2103.03515},
  year   = {2023}
}

Comments

More streamlined exposition following referee's suggestions. Corrected some minor errors in Sections 4 and 5. Main results and statements unchanged

R2 v1 2026-06-23T23:47:27.815Z