English

Categorical absorptions of singularities and degenerations

Algebraic Geometry 2026-05-27 v5

Abstract

We introduce the notion of categorical absorption of singularities: an operation that removes from the derived category of a singular variety a small admissible subcategory responsible for singularity and leaves a smooth and proper category. We construct (under appropriate assumptions) a categorical absorption for a projective variety XX with isolated ordinary double points. We further show that for any smoothing X/B\mathcal{X}/B of XX over a smooth curve BB, the smooth part of the derived category of XX extends to a smooth and proper over BB family of triangulated subcategories in the fibers of X\mathcal{X}.

Keywords

Cite

@article{arxiv.2207.06477,
  title  = {Categorical absorptions of singularities and degenerations},
  author = {Alexander Kuznetsov and Evgeny Shinder},
  journal= {arXiv preprint arXiv:2207.06477},
  year   = {2026}
}

Comments

41 pages; v2, v3: minor improvements, v4: revised according to the referee's report, to appear in EPIGA, v5: published version