English

High Frobenius pushforwards generate the bounded derived category

Algebraic Geometry 2026-01-28 v3 Commutative Algebra

Abstract

This work concerns generators for the bounded derived category of coherent sheaves over a noetherian scheme XX of prime characteristic. The main result is that when the Frobenius map on XX is finite, for any compact generator GG of D(X)\mathsf{D}(X) the Frobenius pushforward FeGF ^e_*G generates the bounded derived category whenever pep^e is larger than the codepth of XX, an invariant that is a measure of the singularity of XX. The conclusion holds for all positive integers ee when XX is locally complete intersection. The question of when one can take G=OXG=\mathcal{O}_X is also investigated. For smooth projective complete intersections it reduces to a question of generation of the Kuznetsov component.

Keywords

Cite

@article{arxiv.2303.18085,
  title  = {High Frobenius pushforwards generate the bounded derived category},
  author = {Matthew R. Ballard and Srikanth B. Iyengar and Pat Lank and Alapan Mukhopadhyay and Josh Pollitz},
  journal= {arXiv preprint arXiv:2303.18085},
  year   = {2026}
}

Comments

32 pages; minor revision. To appear in Forum of Mathematics, Sigma

R2 v1 2026-06-28T09:43:14.199Z